Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can probably retrieve the secret key. In this paper,we analyze the formulas of point doubling and additi...Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can probably retrieve the secret key. In this paper,we analyze the formulas of point doubling and addition on Jacobi-quartic Curve in projective coordination. In addition,a fast and secure side-channel atomic scalar multiplication algorithm is proposed using the side-channel atomic block. Compared with the previous methods,the new algorithm is more efficient. For 192 bits scalar using NAF recoding,the efficiency of the new algorithm is increased by about 6.7%～23% if S/M=0.8 or 12.7%～33.2% if S/M=0.6.展开更多
Platinum clusters(Pt_(n))are extensively used as electrocatalysts for oxygen reduction reaction(ORR)because they provide excellent performance together with a reduced Pt requirement.However,the precise synthesis and a...Platinum clusters(Pt_(n))are extensively used as electrocatalysts for oxygen reduction reaction(ORR)because they provide excellent performance together with a reduced Pt requirement.However,the precise synthesis and atomic-level insights into the structure-activity relationship of Pt_(n) remain a great challenge.Here,we present a combinatorial synthesis and analysis method to investigate the atomicity-activity relationships of Pt_(n) at the individual level.We employ single nanoparticle collision electrochemistry to facilitate the in-situ electrodeposition of a single precisely tunable Pt_(n) on the graphene quantum dot support,followed by instantaneous measurement of the intrinsic ORR activity of the resulting Pt_(n).By relying on highly sensitive electrochemical measurements,our investigations clarify the atomicity-specific ORR activity of Pt_(n),which is attributed to their distinct geometric and electronic structures at varying cluster sizes.Significantly,Pt_(n) with low atomicity,especially below 20,can reach extraordinarily high ORR activities due to atom-by-atom arrangement.Our work provides a simple and efficient method for investigating the atomicity-activity relationships of other nanoclusters under real reaction conditions,enabling a better design of the electrocatalysts at the atomic level.展开更多
In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale in...In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.展开更多
Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom a...Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom arrays,scalability is primarily constrained by the capacity to generate large numbers of optical tweezers,and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond∼10,000 tweezers.Moreover,these methods require additional microscope objectives to focus the light into micrometer-sized spots,which further complicates system integration and scalability.Here,we demonstrate the experimental generation of an optical tweezer array containing 280×280 spots using a metasurface,nearly an order of magnitude more than most existing systems.The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light,enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope.This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power.Furthermore,the array shows excellent intensity uniformity exceeding 90%,making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than 10,000 atoms in the near future.展开更多
The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are d...The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are directly captured using a vapor MOT,while potassium(K)atoms are collected via a 2-stage MOT.Both the quadratic and gradient magnetic fields required for the MOT and Zeeman slower are created by permanent magnets.With the help of the Zeeman slower,the K MOT loading efficiency is enhanced by a factor of three.After the MOT stage,we apply D_(1) gray molasses to reduce the temperature of the K atoms to 9μK.Using this apparatus,both Rb and K are loaded into the optical tweezer.展开更多
Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturiza...Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturization.In particular,the spin-exchange relaxation-free(SERF)atomic gyroscope relies on optical pumping to polarize atoms,enabling rotation sensing through the Faraday optical rotation angle(FORA).However,fluctuations in atomic density introduce systematic errors in FORA measurements,limiting long-term stability.We present a data-driven decoupling method that isolates atomic density fluctuations from the FORA signal by modeling spatially resolved light absorption in the vapor cell.The model accounts for the spatial distribution of spin polarization in the pump-light interaction volume,density-dependent relaxation rates,wall-induced relaxation,and polarization diffusion,and is implemented within a finite-element framework.Compared to the conventional Lambert-Beer law,which assumes one-dimensional homogeneity,our approach captures the full threedimensional density and polarization distribution,significantly improving the accuracy of light absorption modeling.The resulting absorption-density maps are used to train a feedforward neural network,yielding a high-precision estimator for atomic density fluctuations.This estimator enables the construction of a decoupling equation that separates the density contribution from the FORA signal.Experimental validation shows that this method improves the bias instability atσ(100 s)of the gyroscope was improved by 73.1%compared to traditional platinum-resistance-based stabilization.The proposed framework is general and can be extended to other optical pumping-based sensors,such as optically pumped magnetometers.展开更多
Peptide-and drug-protected gold nanoclusters(Au NCs)with atomic precision have attracted research attention in the last few years owing to their ultrasmall size(<2 nm),well-defined structures,tunable photoluminesce...Peptide-and drug-protected gold nanoclusters(Au NCs)with atomic precision have attracted research attention in the last few years owing to their ultrasmall size(<2 nm),well-defined structures,tunable photoluminescence from the visible to near-infrared range,water solubility,and good biocompatibility.These features,combined with low toxicity and efficient renal clearance,make such Au NCs promising candidates for biomedical use,including diagnosis,therapy,and theranostic.The incorporation of peptides or drugs into Au NCs enhances the stability,targeting specificity,cellular uptake,and prolonged circulation,enabling precise modulation of biological responses.Despite notable advances in achieving atomic precision employing complex ligands such as peptides or drugs,the synthetic methods of this new class of NCs remain a challenge.Careful control of molar ratio(Au:peptide/drug),reducing agent,temperature,and reaction time is required,because these factors directly influence the cluster size,optical properties,and in vivo performance.In this review,we highlight different synthetic approaches of atomically precise peptide-and drug-protected Au NCs,emphasizing the role of rational ligand design and reaction conditions,as well as the challenges associated with structural determination.We further discuss the optical and photoluminescence properties of peptide-protected Au NCs-the mostly explored features for biomedical applications.Finally,we conclude by outlining the current challenges,opportunities for scale-up synthesis,and future design perspectives for these emerging nanomaterials.展开更多
The single-atom replacement strategy is a typical approach which just converts elements in lead compounds into their analogues with very small chemical changes.In this research,we implemented this strategy to modify t...The single-atom replacement strategy is a typical approach which just converts elements in lead compounds into their analogues with very small chemical changes.In this research,we implemented this strategy to modify the sulfonamide scaffold identified in our previous work,and resulting in the synthesis of 40 novel sulfonamide derivatives not previously reported in the literature.The insecticidal activities of these compounds against the Mythimna separata and Plutella xylostella were assessed.Our findings indicate that the pyridine sulfonamide structure significantly enhances insecticidal efficacy.Specifically,compound 7c exhibited LC 50 values of 0.157 and 0.256 mg/mL against the M.separata and P.xylostella,which significantly increased 97-and 41-fold compared to celangulin V,respectively.The experimental results revealed that pyridine sulfonamide analogues could serve as potential green insecticides.展开更多
We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and...We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.展开更多
Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the effica...Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.展开更多
The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for syn...The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for synthesizing thioesters primarily rely on the acylation of thiols,which produces substantial waste and requires malodorous,unstable sulfur sources.In this work,we introduce a photocatalyzed hydrogen transfer strategy that enables a three-component synthesis of thioesters using abundant primary alcohols,easily available alkenes and elemental sulfur under mild conditions.This protocol demonstrates broad applicability and high chemo-and regioselectivity for both primary alcohols and alkenes,highlighting the advantage and potential of photo-mediated hydrogen transfer in facilitating multicomponent reactions using primary alcohol and elemental sulfur feedstocks.展开更多
A new type of asymmetric hydrogen atom abstraction catalysts,originated from the cinchona alkaloid family of natural products,has been successfully developed to access enantioselective epimerizations of meso-diols.Aft...A new type of asymmetric hydrogen atom abstraction catalysts,originated from the cinchona alkaloid family of natural products,has been successfully developed to access enantioselective epimerizations of meso-diols.After undergoing single-electron oxidation,the catalyst fulfills desymmetrization of meso-diols by selectively traping a hydrogen atom from a carbon center,which subsequently recaptures a hydrogen atom via abstraction from a thiol.The publication of this work will have a significant influence in the field of asymmetric radical chemistry.展开更多
In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this met...In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this method,the atom interacts with two orthogonal standing-wave fields and a weak probe field.By examining how the weak probe field passes through the system,we can determine the atom position.Our analysis reveals the presence of both double and sharply defined single localized peaks in the transmission spectrum,which correspond to specific positions of the atom.Importantly,we achieve ultra-high-resolution atomic localization with accuracy confined to a region smaller thanλ/32×λ/32.This level of precision is a significant improvement compared to earlier methods,which had lower localization accuracy.The increased precision is due to the complex interaction between the atom and the carefully controlled standing-wave and probe fields,which allows for precise control over the atom's position.The implications of this work are significant,especially for applications like nano-lithography,where precise atomic placement is essential,and for laser cooling technologies,where better atomic localization could lead to more effective cooling processes and improved manipulation of atomic states.展开更多
Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite i...Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite intensive research,the microscopic structure of the premelting layer and underlying molecular mechanisms remain poorly understood.In this work,we studied the temperature-and pressure-dependent structural disordering of crystalline Ih(0001)surface near the onset of premelting on the atomic scale by qPlus-based cryogenic atomic force microscopy.The linear correlation between the density of planar local structure(PLS)and the fraction of disordered surface region showed that the PLS mediated early-stage premelting by serving as a metastable seeding state.Notably,the associated surface disordering is cooperative,extending over an area of roughly~2 nm^(2) around a PLS.We further found a striking structural similarity between the kinetic-trapped regime below the surface crystallization temperature(T_(c))and the premelting-dominated regime above T_(c).As the deposition pressure increased,the characteristic temperature dependence was preserved,with only T_(c) shifting to higher values due to kinetic effects.Finally,we proposed a surface phase diagram for ice Ih(0001)based on our experimental observations.展开更多
Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibite...Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.展开更多
The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulat...The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.展开更多
Porous hydrogel sensors have attracted significant attention in fields such as smart wearables and medical monitoring due to their high sensitivity.However,existing fabrication methods typically degrade the surface sm...Porous hydrogel sensors have attracted significant attention in fields such as smart wearables and medical monitoring due to their high sensitivity.However,existing fabrication methods typically degrade the surface smoothness of hydrogels when introducing porous structures and face significant challenges in removing fillers completely.To address these challenges,we herein introduce a novel one-step,thermosensitive spray-coating technique for the preparation of aircell hydrogel(ACH).This method leverages the rapid cooling of a thermoresponsive gelatin methacryloyl solution through atomization,enabling rapid cross-linking within seconds and air bubbles encapsulated in situ.Additionally,the transient flow of the pre-gel facilitates the repair of voids formed by ruptured surface bubbles,leading to the creation of the ACH with uniformly distributed inner air bubbles and a smooth outer surface.The mold-free fabrication method is independent of substrate surface properties,enabling the creation of a porous hydrogel film with a thickness as thin as 163 µm.Furthermore,the dual-crosslinked network endows the ACH with excellent anti-swelling properties,and the physical crosslinking between gelatin molecules allows the ACH to self-heal.The ACH exhibits excellent sensitivity in deformation sensing and can even successfully track minor external forces,which enables it to effectively complete various tasks such as facial expression recognition,pitch differentiation,and motion detection.By integrating the ACH into a sensing glove,we also demonstrate the significant potential of the ACH for applications in human-machine interaction and tactile sensing.Ultimately,the ACH sensors are also applied to motion mapping and machine tactile feedback,indicating their promising potential in human-machine interaction.展开更多
We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system...We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system incorporates two auxiliary cavities and an atomic ensemble coupled to a Laguerre-Gaussian rotational cavity.By carefully selecting system parameters,the cooling process of the rotating mirror is significantly enhanced,while the heating process is effectively suppressed,enabling efficient ground-state cooling even in the unresolved sideband regime.Compared to previous works,our scheme reduces the stringent restrictions on auxiliary systems,making it more experimentally feasible under broader parameter conditions.These findings provide a robust approach for achieving ground-state cooling in mechanical resonators.展开更多
We developed a model of a quantum Otto engine using two coupled two-level atoms.Based on the platform,we show that frequency detuning and the coupling strength induced by dipoledipole interactions can lead to decohere...We developed a model of a quantum Otto engine using two coupled two-level atoms.Based on the platform,we show that frequency detuning and the coupling strength induced by dipoledipole interactions can lead to decoherence by disrupting coherent energy exchange.We focus on fundamental thermodynamic quantities,including heat absorption,release to heat baths,work done and efficiency.It is noteworthy that the interatomic coupling strength and frequency detuning do not merely affect the shape of the work and the efficiency but ultimately govern its quantitative magnitude.In the field of quantum thermodynamics,we have established an upper bound efficiency that is stricter than the Carnot limit.Moreover,our analysis confirms that quantum coherence enables the system to exceed the efficiency threshold of a classical Otto heat engine.The second law of thermodynamics holds all the while.Our results constitute a step forward in the design of conceptually new quantum thermodynamic devices which take advantage of uniquely quantum resources of quantum coherence.展开更多
基金sponsored and financial supported by National Natural Science Foundation of China (NSFC), grant No.61003121Sichuan Province High Technology Program under No.2009CD00014
文摘Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can probably retrieve the secret key. In this paper,we analyze the formulas of point doubling and addition on Jacobi-quartic Curve in projective coordination. In addition,a fast and secure side-channel atomic scalar multiplication algorithm is proposed using the side-channel atomic block. Compared with the previous methods,the new algorithm is more efficient. For 192 bits scalar using NAF recoding,the efficiency of the new algorithm is increased by about 6.7%～23% if S/M=0.8 or 12.7%～33.2% if S/M=0.6.
基金financially supported by the National Natural Science Foundation of China(22272052)the Major Research Project(92061108)the Science and Technology Commission of Shanghai Municipality(24DX1400200)。
文摘Platinum clusters(Pt_(n))are extensively used as electrocatalysts for oxygen reduction reaction(ORR)because they provide excellent performance together with a reduced Pt requirement.However,the precise synthesis and atomic-level insights into the structure-activity relationship of Pt_(n) remain a great challenge.Here,we present a combinatorial synthesis and analysis method to investigate the atomicity-activity relationships of Pt_(n) at the individual level.We employ single nanoparticle collision electrochemistry to facilitate the in-situ electrodeposition of a single precisely tunable Pt_(n) on the graphene quantum dot support,followed by instantaneous measurement of the intrinsic ORR activity of the resulting Pt_(n).By relying on highly sensitive electrochemical measurements,our investigations clarify the atomicity-specific ORR activity of Pt_(n),which is attributed to their distinct geometric and electronic structures at varying cluster sizes.Significantly,Pt_(n) with low atomicity,especially below 20,can reach extraordinarily high ORR activities due to atom-by-atom arrangement.Our work provides a simple and efficient method for investigating the atomicity-activity relationships of other nanoclusters under real reaction conditions,enabling a better design of the electrocatalysts at the atomic level.
基金Supported by the National Natural Science Foundation of China(11871195)。
文摘In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.
基金supported by the National Natural Science Foundation of China (Grant No.92576208)Tsinghua University Initiative Scientific Research Program+1 种基金Beijing Science and Technology Planning ProjectTsinghua University Dushi Program。
文摘Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom arrays,scalability is primarily constrained by the capacity to generate large numbers of optical tweezers,and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond∼10,000 tweezers.Moreover,these methods require additional microscope objectives to focus the light into micrometer-sized spots,which further complicates system integration and scalability.Here,we demonstrate the experimental generation of an optical tweezer array containing 280×280 spots using a metasurface,nearly an order of magnitude more than most existing systems.The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light,enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope.This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power.Furthermore,the array shows excellent intensity uniformity exceeding 90%,making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than 10,000 atoms in the near future.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406703 and 2022YFA1404203)the National Natural Science Foundation of China(Grant Nos.12425408,U21A20437 and 12074337)+1 种基金the Natural Science Foundation of Zhejiang Province,China(Grant No.LR21A040002)the Fundamental Research Funds for the Central Universities(Grant No.226-2023-00131)。
文摘The optical tweezer experiment with neutral atoms is widely used for quantum information research.Here,we present a compact dual magneto-optical trap(MOT)setup for a two-species optical tweezer.Rubidium(Rb)atoms are directly captured using a vapor MOT,while potassium(K)atoms are collected via a 2-stage MOT.Both the quadratic and gradient magnetic fields required for the MOT and Zeeman slower are created by permanent magnets.With the help of the Zeeman slower,the K MOT loading efficiency is enhanced by a factor of three.After the MOT stage,we apply D_(1) gray molasses to reduce the temperature of the K atoms to 9μK.Using this apparatus,both Rb and K are loaded into the optical tweezer.
基金supported by the Beijing Natural Science Foundation(Grant No.3252013)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300402)+1 种基金the National Natural Science Foundation of China(Grant No.61673041)Key Area Research and Development Program of Guangdong Province(Grant No.2021B0101410005)。
文摘Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturization.In particular,the spin-exchange relaxation-free(SERF)atomic gyroscope relies on optical pumping to polarize atoms,enabling rotation sensing through the Faraday optical rotation angle(FORA).However,fluctuations in atomic density introduce systematic errors in FORA measurements,limiting long-term stability.We present a data-driven decoupling method that isolates atomic density fluctuations from the FORA signal by modeling spatially resolved light absorption in the vapor cell.The model accounts for the spatial distribution of spin polarization in the pump-light interaction volume,density-dependent relaxation rates,wall-induced relaxation,and polarization diffusion,and is implemented within a finite-element framework.Compared to the conventional Lambert-Beer law,which assumes one-dimensional homogeneity,our approach captures the full threedimensional density and polarization distribution,significantly improving the accuracy of light absorption modeling.The resulting absorption-density maps are used to train a feedforward neural network,yielding a high-precision estimator for atomic density fluctuations.This estimator enables the construction of a decoupling equation that separates the density contribution from the FORA signal.Experimental validation shows that this method improves the bias instability atσ(100 s)of the gyroscope was improved by 73.1%compared to traditional platinum-resistance-based stabilization.The proposed framework is general and can be extended to other optical pumping-based sensors,such as optically pumped magnetometers.
基金RGM is grateful to CNPq for the PDE fellowship(200437/2025-9),MTM acknowledges CNPq research scholarship(314470/2023-9)FAPESP fundings(2022/01825-22025/063196).
文摘Peptide-and drug-protected gold nanoclusters(Au NCs)with atomic precision have attracted research attention in the last few years owing to their ultrasmall size(<2 nm),well-defined structures,tunable photoluminescence from the visible to near-infrared range,water solubility,and good biocompatibility.These features,combined with low toxicity and efficient renal clearance,make such Au NCs promising candidates for biomedical use,including diagnosis,therapy,and theranostic.The incorporation of peptides or drugs into Au NCs enhances the stability,targeting specificity,cellular uptake,and prolonged circulation,enabling precise modulation of biological responses.Despite notable advances in achieving atomic precision employing complex ligands such as peptides or drugs,the synthetic methods of this new class of NCs remain a challenge.Careful control of molar ratio(Au:peptide/drug),reducing agent,temperature,and reaction time is required,because these factors directly influence the cluster size,optical properties,and in vivo performance.In this review,we highlight different synthetic approaches of atomically precise peptide-and drug-protected Au NCs,emphasizing the role of rational ligand design and reaction conditions,as well as the challenges associated with structural determination.We further discuss the optical and photoluminescence properties of peptide-protected Au NCs-the mostly explored features for biomedical applications.Finally,we conclude by outlining the current challenges,opportunities for scale-up synthesis,and future design perspectives for these emerging nanomaterials.
基金supported by the National Natural Science Foundation of China[Grant No.21977083].
文摘The single-atom replacement strategy is a typical approach which just converts elements in lead compounds into their analogues with very small chemical changes.In this research,we implemented this strategy to modify the sulfonamide scaffold identified in our previous work,and resulting in the synthesis of 40 novel sulfonamide derivatives not previously reported in the literature.The insecticidal activities of these compounds against the Mythimna separata and Plutella xylostella were assessed.Our findings indicate that the pyridine sulfonamide structure significantly enhances insecticidal efficacy.Specifically,compound 7c exhibited LC 50 values of 0.157 and 0.256 mg/mL against the M.separata and P.xylostella,which significantly increased 97-and 41-fold compared to celangulin V,respectively.The experimental results revealed that pyridine sulfonamide analogues could serve as potential green insecticides.
基金Funded by the National Natural Science Foundation of China(No.52371169)。
文摘We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.
基金supported by the National Key R&D Program of China (2021YFA1502802)the National Natural Science Foundation of China (U21B2092, 22202213, 22402210, 22502215, 22502214, 22572200, and 22579171)+3 种基金the International Partnership Program of Chinese Academy of Sciences (172GJHZ2022028MI)the Shenyang Bureau of Science and Technology (24-213-3-25)the Natural Science Foundation of Liaoning Province (2025BS0153)Zhongke Technology Achievement Transfer and Transformation Center of Henan Province 2025119
文摘Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
基金National Natural Science Foundation of China (Nos.22071185 and 22271224)the Fundamental Research Funds for the Central Universities (No.2042019kf0008)Wuhan University startup funding for financial support。
文摘The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for synthesizing thioesters primarily rely on the acylation of thiols,which produces substantial waste and requires malodorous,unstable sulfur sources.In this work,we introduce a photocatalyzed hydrogen transfer strategy that enables a three-component synthesis of thioesters using abundant primary alcohols,easily available alkenes and elemental sulfur under mild conditions.This protocol demonstrates broad applicability and high chemo-and regioselectivity for both primary alcohols and alkenes,highlighting the advantage and potential of photo-mediated hydrogen transfer in facilitating multicomponent reactions using primary alcohol and elemental sulfur feedstocks.
基金supported by the National Natural Science Foundation of China(No.22208302)the Natural Science Foundation of Zhejiang Province of China(LQ21B020006).
文摘A new type of asymmetric hydrogen atom abstraction catalysts,originated from the cinchona alkaloid family of natural products,has been successfully developed to access enantioselective epimerizations of meso-diols.After undergoing single-electron oxidation,the catalyst fulfills desymmetrization of meso-diols by selectively traping a hydrogen atom from a carbon center,which subsequently recaptures a hydrogen atom via abstraction from a thiol.The publication of this work will have a significant influence in the field of asymmetric radical chemistry.
基金Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R8)。
文摘In this article,we introduce a new theoretical approach to improve the accuracy of twodimensional(2D)atomic localization within a tripod-type,four-level atomic system by analyzing its transmission spectrum.In this method,the atom interacts with two orthogonal standing-wave fields and a weak probe field.By examining how the weak probe field passes through the system,we can determine the atom position.Our analysis reveals the presence of both double and sharply defined single localized peaks in the transmission spectrum,which correspond to specific positions of the atom.Importantly,we achieve ultra-high-resolution atomic localization with accuracy confined to a region smaller thanλ/32×λ/32.This level of precision is a significant improvement compared to earlier methods,which had lower localization accuracy.The increased precision is due to the complex interaction between the atom and the carefully controlled standing-wave and probe fields,which allows for precise control over the atom's position.The implications of this work are significant,especially for applications like nano-lithography,where precise atomic placement is essential,and for laser cooling technologies,where better atomic localization could lead to more effective cooling processes and improved manipulation of atomic states.
基金Project supported by the National Key R&D Program of China(Grant Nos.2021YFA1400500 and 2025YFF1502400)the National Natural Science Foundation of China(Grant Nos.92361302,12250001,12535001,and U22A20260)+3 种基金the China Postdoctoral Science Foundation(Grant Nos.BX20230021,2023T160011,and 2024M760068)support from the National Program for Support of Top-notch Young professionalssupport from Beijing Outstanding Young Scientist Program(Grant No.JWZQ20240101002)the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZE。
文摘Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite intensive research,the microscopic structure of the premelting layer and underlying molecular mechanisms remain poorly understood.In this work,we studied the temperature-and pressure-dependent structural disordering of crystalline Ih(0001)surface near the onset of premelting on the atomic scale by qPlus-based cryogenic atomic force microscopy.The linear correlation between the density of planar local structure(PLS)and the fraction of disordered surface region showed that the PLS mediated early-stage premelting by serving as a metastable seeding state.Notably,the associated surface disordering is cooperative,extending over an area of roughly~2 nm^(2) around a PLS.We further found a striking structural similarity between the kinetic-trapped regime below the surface crystallization temperature(T_(c))and the premelting-dominated regime above T_(c).As the deposition pressure increased,the characteristic temperature dependence was preserved,with only T_(c) shifting to higher values due to kinetic effects.Finally,we proposed a surface phase diagram for ice Ih(0001)based on our experimental observations.
基金supported by the National Natural Science Foundation of China(Nos.22406081,22276086,22306086)the Natural Science Foundation of Jiangxi Province(No.20232BAB213029),all of which are greatly acknowledged by the authors.
文摘Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.
基金supported by the National Natural Science Foundation of China(52402166)the Science and Technology Development Fund+2 种基金Macao SAR(0065/2023/AFJ,0116/2022/A3)the Australian Research Council(DE220100154)the Natural Science Foundation of Guangdong Province(2025A1515011120)。
文摘The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.
基金financially supported by the National Key R&D Program of China(Grant No.2023YFE0108900)EU HORIZON 2021 L4DNANO(No.101086227)。
文摘Porous hydrogel sensors have attracted significant attention in fields such as smart wearables and medical monitoring due to their high sensitivity.However,existing fabrication methods typically degrade the surface smoothness of hydrogels when introducing porous structures and face significant challenges in removing fillers completely.To address these challenges,we herein introduce a novel one-step,thermosensitive spray-coating technique for the preparation of aircell hydrogel(ACH).This method leverages the rapid cooling of a thermoresponsive gelatin methacryloyl solution through atomization,enabling rapid cross-linking within seconds and air bubbles encapsulated in situ.Additionally,the transient flow of the pre-gel facilitates the repair of voids formed by ruptured surface bubbles,leading to the creation of the ACH with uniformly distributed inner air bubbles and a smooth outer surface.The mold-free fabrication method is independent of substrate surface properties,enabling the creation of a porous hydrogel film with a thickness as thin as 163 µm.Furthermore,the dual-crosslinked network endows the ACH with excellent anti-swelling properties,and the physical crosslinking between gelatin molecules allows the ACH to self-heal.The ACH exhibits excellent sensitivity in deformation sensing and can even successfully track minor external forces,which enables it to effectively complete various tasks such as facial expression recognition,pitch differentiation,and motion detection.By integrating the ACH into a sensing glove,we also demonstrate the significant potential of the ACH for applications in human-machine interaction and tactile sensing.Ultimately,the ACH sensors are also applied to motion mapping and machine tactile feedback,indicating their promising potential in human-machine interaction.
基金Project supported by the National Natural Science Foundation of China(Grant No.62471180)。
文摘We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system incorporates two auxiliary cavities and an atomic ensemble coupled to a Laguerre-Gaussian rotational cavity.By carefully selecting system parameters,the cooling process of the rotating mirror is significantly enhanced,while the heating process is effectively suppressed,enabling efficient ground-state cooling even in the unresolved sideband regime.Compared to previous works,our scheme reduces the stringent restrictions on auxiliary systems,making it more experimentally feasible under broader parameter conditions.These findings provide a robust approach for achieving ground-state cooling in mechanical resonators.
基金supported by University-Industry Collaborative Education Program(Project No.220506627183928)。
文摘We developed a model of a quantum Otto engine using two coupled two-level atoms.Based on the platform,we show that frequency detuning and the coupling strength induced by dipoledipole interactions can lead to decoherence by disrupting coherent energy exchange.We focus on fundamental thermodynamic quantities,including heat absorption,release to heat baths,work done and efficiency.It is noteworthy that the interatomic coupling strength and frequency detuning do not merely affect the shape of the work and the efficiency but ultimately govern its quantitative magnitude.In the field of quantum thermodynamics,we have established an upper bound efficiency that is stricter than the Carnot limit.Moreover,our analysis confirms that quantum coherence enables the system to exceed the efficiency threshold of a classical Otto heat engine.The second law of thermodynamics holds all the while.Our results constitute a step forward in the design of conceptually new quantum thermodynamic devices which take advantage of uniquely quantum resources of quantum coherence.
