We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body ...We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body interactions and the disorder, the coherence of the system exhibits new and interesting phenomena, including the resonance character of coherence against the disorder in the purely two- or three-body interactions system. More interestingly, the disorder and three-body interactions together can suppress the coherence of the purely three-body interactions system, which is different from the case in which the disorder and two-body interactions together can enhance the coherence in certain values of two.body interaction. Furthermore, when two- or three- body interactions are attractive or repulsive, the phase coherence exhibits completely different phenomena. In particular, if two- or three-body interactions are attractive, the coherence of the system can be significantly enhanced in certain regions. Correspondingly, the phase coherence of the system is strongly related to the effective interaction energy. The results provide a possible way for studying the coherence of bosonic gas with multi-atoms＇ interactions in the presence of the disorder.展开更多
Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we de...Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we derive new contour integration expression of associated Laguerre polynomials L^ρm （｜z｜^2） and its generalized generating function formula. A series of recursive relations regarding to L^ρm （｜z｜^2） are also deduced in the context of the Fock representation by algebraic method.展开更多
From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin f...From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin film brick wall model of black hole, which is introduced by LIU Weng-Biao and ZHAO Zheng, we obtain the bosonic and fermionic entropy of (2+1)-dimensional charged black hole, and find that the bosonic entropy is three times of fermionic entropy.展开更多
We quantify the nonclassicality of multimode bosonic field states by adopting an information-theoretic approach involving the Wigner-Yanase skew information.The fundamental properties of the quantifier such as convexi...We quantify the nonclassicality of multimode bosonic field states by adopting an information-theoretic approach involving the Wigner-Yanase skew information.The fundamental properties of the quantifier such as convexity,superadditivity,monotonicity,and conservation relations are revealed.The quantifier is illustrated by a variety of typical examples,and applications to the quantification of nonclassical correlations are discussed.Various extensions are indicated.展开更多
We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single...We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.展开更多
In this letter,we have studied quantum tunneling of two-species cold bosonic atoms in an optical lattices.When the optical lattice is not infinitely long and the spin excitations are not in the long-wavelength limit,q...In this letter,we have studied quantum tunneling of two-species cold bosonic atoms in an optical lattices.When the optical lattice is not infinitely long and the spin excitations are not in the long-wavelength limit,quantumtunnelings are presented.展开更多
In this paper,by employing an occasionally coupling scheme in a two-species bosonic Josephson junction,it is found that for nonlocal measure synchronized states appearing in the two dynamic modes,known as 0-phase mode...In this paper,by employing an occasionally coupling scheme in a two-species bosonic Josephson junction,it is found that for nonlocal measure synchronized states appearing in the two dynamic modes,known as 0-phase mode andπphase mode,their broken-symmetry can be restored.Nevertheless,there are dramatic differences for the results.For 0-phase mode,we can restore the broken symmetry by turning the nonlocal MS state into a conventional quasiperiodic MS state.However,for theπ-phase mode,the broken symmetry is restored accompanied by the appearance of chaotic MS states.展开更多
We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±,...We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±, Jz） from the point of view of squeezing we find that （J±,Jz） can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation （the eigenvectors of J＋ or J-） of the 3-mode squeezing operator e^2λJz. The idea of considering quantum SU（2） transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU（2） and new squeezing operators.展开更多
Super-high resolution laser-based angle-resolved photoemission measurements are carried out on LiFeAs superconductor to investigate its electron dynamics. Three energy scales at ~ 20 meV, ~ 34 meV, and ~ 55 meV are re...Super-high resolution laser-based angle-resolved photoemission measurements are carried out on LiFeAs superconductor to investigate its electron dynamics. Three energy scales at ~ 20 meV, ~ 34 meV, and ~ 55 meV are revealed for the first time in the electron self-energy both in the superconducting state and normal state. The ~ 20 meV and ~ 34 meV scales can be attributed to the coupling of electrons with sharp bosonic modes which are most likely phonons. These observations provide definitive evidence on the existence of mode coupling in iron-based superconductors.展开更多
Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> o...Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> of 1/2<span style="white-space:nowrap;"><em><span style="white-space:nowrap;">ħ</span></em></span>. An orbital containing a single electron with <em>s</em> = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins,<em> i.e.</em>, spin magnetic quantum numbers <em>m</em><sub><em>s</em></sub> of 1/2 and -1/2. An orbital filled by an electron couple has <em>s</em> = 0 and bosonic character. The multiplicity of a reactant is defined as |2(<em>S</em>)| + 1 where <em>S</em> is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient <em>κ</em> of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O<sub>2</sub>. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O<sub>2</sub> from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O<sub>2</sub>, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (<span style="white-space:nowrap;"><sup>1</sup>O<sub>2</sub><sup style="margin-left:-10px;">*</sup></span><span style="font-size:10px;white-space:nowrap;">).</span> Hydride ion (H<sup>-</sup>) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O<sub>2</sub>. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.展开更多
Engineering spin polarization in dissipative bosonic systems is crucial for advancing quantum technologies,especially for applications in quantum metrology and space-based quantum simulations.This work demonstrates pr...Engineering spin polarization in dissipative bosonic systems is crucial for advancing quantum technologies,especially for applications in quantum metrology and space-based quantum simulations.This work demonstrates precise magnetic moment control in multicomponent Bose gases during evaporative cooling via tailored magnetic fields.By adjusting the magnetic field gradients,null point position,and duration,we selectively tune evap-oration rates of magnetic sublevels,achieving targeted spin polarization.Theoretical models,validated by numerical simulations and Stern–Gerlach experiments,reveal how magnetic fields reshape trapping poten-tials and spin-dependent dissipation.The results establish a dissipative spin-selection mechanism governing polarization evolution in evapora-tively cooled Bose gases and provide a framework for engineering spin-polarized quantum states.展开更多
In dissipative bosonic systems,dephasing is typically expected to accelerate relaxation and suppress coherent dynamics.However,we show that in networks of coherently coupled bosonic modes with non-uniform local dissip...In dissipative bosonic systems,dephasing is typically expected to accelerate relaxation and suppress coherent dynamics.However,we show that in networks of coherently coupled bosonic modes with non-uniform local dissipation,the presence of quasi-dark states leads to a nontrivial response to dephasing:while weak dephasing facilitates equilibration,moderate to strong dephasing induces a pronounced slowdown of relaxation,revealing the existence of an optimal dephasing rate that enhances equilibration.Using exact dynamical equations for second-order moments,we demonstrate that dephasing suppresses coherent transport and gives rise to longlived collective modes that dominate the system’s late-time behavior.This phenomenon bears striking similarities to Lifshitz-tail states,which are known in disordered systems to cause anomalously slow relaxation.Our results uncover a counterintuitive mechanism by which dephasing,rather than promoting equilibration,can dynamically decouple specific modes from dissipation,thereby protecting excitations.These findings highlight how non-Hermitian physics in open bosonic systems can give rise to unexpected dynamical regimes,paving the way for new strategies to control relaxation and decoherence in bosonic quantum systems,with broad implications for both experimental and theoretical quantum science.展开更多
We show that the compact star XTE J1814-338 can be explained as a strange star admixed with self-interacting bosonic dark matter(BDM),provided the dark matter fraction exceeds approximately 70%.This interpretation lea...We show that the compact star XTE J1814-338 can be explained as a strange star admixed with self-interacting bosonic dark matter(BDM),provided the dark matter fraction exceeds approximately 70%.This interpretation leads to a robust constraint on the BDM particle mass:mx■307(λ/π)^(1/4)MeV(λ is the dimensionless coupling constant of the BDM).The result is independent of formation scenario and microphysical details and is falsifiable by future NICER and LIGO/Virgo observations.展开更多
Ultralight vector particles can form evolving condensates around a Kerr black hole(BH)due to superradiant instability.We study the effect of near-horizon reflection on the evolution of this system:by matching three pi...Ultralight vector particles can form evolving condensates around a Kerr black hole(BH)due to superradiant instability.We study the effect of near-horizon reflection on the evolution of this system:by matching three pieces of asymptotic expansions of the Proca equation in Kerr metric and considering the leading order in the electric mode,we present explicit analytical expressions for the corrected spectrum and the superradiant instability rates.Particularly,in high-spin BH cases,we identify an anomalous situation where the superradiance rate is temporarily increased by the reflection parameter R,which also occurs in the scalar scenario,but is largely magnified in vector condensates due to a faster growth rate in dominant mode.We point out that the condition for the growth anomaly in the adiabatic case is that information carried per particle exceeds a certain value δ1/δN>2πκ_(B)√(1+R)/(1-R).We further construct several featured quantities to illustrate it,and formalize the anomalyinduced gravitational wave strain deformation.展开更多
Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect q...Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect quantum information against noise is vital for universal and scalable quantum computation.Among many different experimental platforms,superconducting quantum circuits and bosonic encodings in superconducting microwave modes are appealing for their unprecedented potential in QEC.During the last few years,bosonic QEC is demonstrated to reach the break-even point,i.e.the lifetime of a logical qubit is enhanced to exceed that of any individual components composing the experimental system.Beyond that,universal gate sets and fault-tolerant operations on the bosonic codes are also realized,pushing quantum information processing towards the QEC era.In this article,we review the recent progress of the bosonic codes,including the Gottesman-Kitaev-Preskill codes,cat codes,and binomial codes,and discuss the opportunities of bosonic codes in various quantum applications,ranging from fault-tolerant quantum computation to quantum metrology.We also summarize the challenges associated with the bosonic codes and provide an outlook for the potential research directions in the long terms.展开更多
Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible micr...Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible microwave-to-optical quantum transduction.There is emerging interest in utilizing bosonic modes for quantum information processing,with circuit quantum electrodynamics(circuit QED)as one of the leading architectures.Quantum information can be encoded into subspaces of a bosonic superconducting cavity mode with long coherence time.However,standard Gaussian operations(e.g.,beam splitting and two-mode squeezing)are insufficient for universal quantum computing.The major challenge is to introduce additional nonlinear control beyond Gaussian operations without adding significant bosonic loss or decoherence.Here we review recent advances in universal control of a single bosonic code with superconducting circuits,including unitary control,quantum feedback control,drivendissipative control and holonomic dissipative control.Various approaches to entangling different bosonic modes are also discussed.展开更多
A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra...A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra Vir, a bosonic construction and the same decomposition for Vir are obtained.展开更多
We explore the potential of conducting an experiment in a low Earth orbit spacecraft and using the Earth as a spin and mass source to constrain beyond-the-standard-model(BSM)long-range spin-and velocity-dependent inte...We explore the potential of conducting an experiment in a low Earth orbit spacecraft and using the Earth as a spin and mass source to constrain beyond-the-standard-model(BSM)long-range spin-and velocity-dependent interactions,which are mediated by the exchange of an ultralight(m_(Z')<10^(-10)eV)or massless intermediate vector boson.The high speed of low-Earth-orbit spacecraft can enhance their sensitivity to velocity-dependent interactions.This periodicity enables efficient signal extraction from background noise,thereby improving the accuracy of the experiment.Combining these advantages,we theoretically demonstrate that the novel spacecraft-Earth model can improve the existing bounds on these exotic interactions by up to three orders of magnitude using the China Space Station(CSS)as a representative low-Earthorbit carrier.If successfully implemented,this model may provide an innovative strategy for detecting ultralight dark matter and yield tighter constraints on certain coupling constants of exotic interactions.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11475027,11274255 and 11305132the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grand No 20136203110001+1 种基金the Natural Science Foundation of Gansu Province under Grant No 1506RJYA131the Creation of Science and Technology of Northwest Normal University under Grant Nos NWNU-KJCXGC-03-48 and NWNU-LKQN-12-12
文摘We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body interactions and the disorder, the coherence of the system exhibits new and interesting phenomena, including the resonance character of coherence against the disorder in the purely two- or three-body interactions system. More interestingly, the disorder and three-body interactions together can suppress the coherence of the purely three-body interactions system, which is different from the case in which the disorder and two-body interactions together can enhance the coherence in certain values of two.body interaction. Furthermore, when two- or three- body interactions are attractive or repulsive, the phase coherence exhibits completely different phenomena. In particular, if two- or three-body interactions are attractive, the coherence of the system can be significantly enhanced in certain regions. Correspondingly, the phase coherence of the system is strongly related to the effective interaction energy. The results provide a possible way for studying the coherence of bosonic gas with multi-atoms＇ interactions in the presence of the disorder.
基金supported by the Specialized Research Fund for the Doctorial Progress of Higher Education of China under Grant No.20070358009
文摘Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we derive new contour integration expression of associated Laguerre polynomials L^ρm （｜z｜^2） and its generalized generating function formula. A series of recursive relations regarding to L^ρm （｜z｜^2） are also deduced in the context of the Fock representation by algebraic method.
文摘From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin film brick wall model of black hole, which is introduced by LIU Weng-Biao and ZHAO Zheng, we obtain the bosonic and fermionic entropy of (2+1)-dimensional charged black hole, and find that the bosonic entropy is three times of fermionic entropy.
基金supported by the National Key R&D Program of China,Grant No.2020YFA0712700the National Natural Science Foundation of China,Grant Nos.11875317and 61833010。
文摘We quantify the nonclassicality of multimode bosonic field states by adopting an information-theoretic approach involving the Wigner-Yanase skew information.The fundamental properties of the quantifier such as convexity,superadditivity,monotonicity,and conservation relations are revealed.The quantifier is illustrated by a variety of typical examples,and applications to the quantification of nonclassical correlations are discussed.Various extensions are indicated.
基金Supported by the National Natural Science Foundation of China under Grant No.11274054the Creative Project of Graduate in University of Suzhou Science and Technology in No.SKCX16-006the Innovation Project of Graduate Education of Jiangsu Province No.JGLX15-150
文摘We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.
基金the Beijing Natural Science Foundation under Grant No.1072010
文摘In this letter,we have studied quantum tunneling of two-species cold bosonic atoms in an optical lattices.When the optical lattice is not infinitely long and the spin excitations are not in the long-wavelength limit,quantumtunnelings are presented.
基金supported by the National Natural Science Foundation of China(Grant No.11791240559,No.11611540330,No.11402199)the Natural Science Foundation of Shaanxi Province(Grant No.2018JM1050,No.2014JQ1022)the Education Department Foundation of Shaanxi Province(Grant No.14JK1676)。
文摘In this paper,by employing an occasionally coupling scheme in a two-species bosonic Josephson junction,it is found that for nonlocal measure synchronized states appearing in the two dynamic modes,known as 0-phase mode andπphase mode,their broken-symmetry can be restored.Nevertheless,there are dramatic differences for the results.For 0-phase mode,we can restore the broken symmetry by turning the nonlocal MS state into a conventional quasiperiodic MS state.However,for theπ-phase mode,the broken symmetry is restored accompanied by the appearance of chaotic MS states.
基金supported by the National Natural Science Foundation of China(Grant Nos.11175113 and 11275123)the Key Project of Natural Science Fund of Anhui Province,China(Grant No.KJ2013A261)
文摘We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±, Jz） from the point of view of squeezing we find that （J±,Jz） can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation （the eigenvectors of J＋ or J-） of the 3-mode squeezing operator e^2λJz. The idea of considering quantum SU（2） transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU（2） and new squeezing operators.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0300300,2016YFA0300600,2017YFA0302900,2018YFA0704200,2018YFA0305600,and 2019YFA0308000)the National Natural Science Foundation of China(Grant Nos.11888101,11922414,and 11874405)+2 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant Nos.XDB25000000 and XDB33010300)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2017013)the Research Program of Beijing Academy of Quantum Information Sciences(Grant No.Y18G06)。
文摘Super-high resolution laser-based angle-resolved photoemission measurements are carried out on LiFeAs superconductor to investigate its electron dynamics. Three energy scales at ~ 20 meV, ~ 34 meV, and ~ 55 meV are revealed for the first time in the electron self-energy both in the superconducting state and normal state. The ~ 20 meV and ~ 34 meV scales can be attributed to the coupling of electrons with sharp bosonic modes which are most likely phonons. These observations provide definitive evidence on the existence of mode coupling in iron-based superconductors.
文摘Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> of 1/2<span style="white-space:nowrap;"><em><span style="white-space:nowrap;">ħ</span></em></span>. An orbital containing a single electron with <em>s</em> = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins,<em> i.e.</em>, spin magnetic quantum numbers <em>m</em><sub><em>s</em></sub> of 1/2 and -1/2. An orbital filled by an electron couple has <em>s</em> = 0 and bosonic character. The multiplicity of a reactant is defined as |2(<em>S</em>)| + 1 where <em>S</em> is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient <em>κ</em> of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O<sub>2</sub>. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O<sub>2</sub> from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O<sub>2</sub>, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (<span style="white-space:nowrap;"><sup>1</sup>O<sub>2</sub><sup style="margin-left:-10px;">*</sup></span><span style="font-size:10px;white-space:nowrap;">).</span> Hydride ion (H<sup>-</sup>) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O<sub>2</sub>. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA0718300 and 2021YFA1400900)the National Natural Science Foundation of China(Grant Nos.11920101004,11934002,92365208)the Space Application System of China Manned Space Program。
文摘Engineering spin polarization in dissipative bosonic systems is crucial for advancing quantum technologies,especially for applications in quantum metrology and space-based quantum simulations.This work demonstrates precise magnetic moment control in multicomponent Bose gases during evaporative cooling via tailored magnetic fields.By adjusting the magnetic field gradients,null point position,and duration,we selectively tune evap-oration rates of magnetic sublevels,achieving targeted spin polarization.Theoretical models,validated by numerical simulations and Stern–Gerlach experiments,reveal how magnetic fields reshape trapping poten-tials and spin-dependent dissipation.The results establish a dissipative spin-selection mechanism governing polarization evolution in evapora-tively cooled Bose gases and provide a framework for engineering spin-polarized quantum states.
文摘In dissipative bosonic systems,dephasing is typically expected to accelerate relaxation and suppress coherent dynamics.However,we show that in networks of coherently coupled bosonic modes with non-uniform local dissipation,the presence of quasi-dark states leads to a nontrivial response to dephasing:while weak dephasing facilitates equilibration,moderate to strong dephasing induces a pronounced slowdown of relaxation,revealing the existence of an optimal dephasing rate that enhances equilibration.Using exact dynamical equations for second-order moments,we demonstrate that dephasing suppresses coherent transport and gives rise to longlived collective modes that dominate the system’s late-time behavior.This phenomenon bears striking similarities to Lifshitz-tail states,which are known in disordered systems to cause anomalously slow relaxation.Our results uncover a counterintuitive mechanism by which dephasing,rather than promoting equilibration,can dynamically decouple specific modes from dissipation,thereby protecting excitations.These findings highlight how non-Hermitian physics in open bosonic systems can give rise to unexpected dynamical regimes,paving the way for new strategies to control relaxation and decoherence in bosonic quantum systems,with broad implications for both experimental and theoretical quantum science.
基金supported by the National Key R&D Program of China(Grant No.2021YFA0718500)。
文摘We show that the compact star XTE J1814-338 can be explained as a strange star admixed with self-interacting bosonic dark matter(BDM),provided the dark matter fraction exceeds approximately 70%.This interpretation leads to a robust constraint on the BDM particle mass:mx■307(λ/π)^(1/4)MeV(λ is the dimensionless coupling constant of the BDM).The result is independent of formation scenario and microphysical details and is falsifiable by future NICER and LIGO/Virgo observations.
基金supported by the National Natural Science Foundation of China(Grant Nos.12147163,and 12175099)supported by the National Natural Science Foundation of China(Grant No.12075136)+5 种基金supported by the National Natural Science Foundation of China(Grant No.12247128)supported by the National Natural Science Foundation of China(Grant Nos.11975072,11835009,and 12473001)supported by Jiangsu Funding Program for Excellent Postdoctoral Talentthe Natural Science Foundation of Shandong Province(Grant No.ZR2020MA094)the National SKA Program of China(Grant Nos.2022SKA0110200,and 2022SKA0110203)the 111 Project(Grant No.B16009)。
文摘Ultralight vector particles can form evolving condensates around a Kerr black hole(BH)due to superradiant instability.We study the effect of near-horizon reflection on the evolution of this system:by matching three pieces of asymptotic expansions of the Proca equation in Kerr metric and considering the leading order in the electric mode,we present explicit analytical expressions for the corrected spectrum and the superradiant instability rates.Particularly,in high-spin BH cases,we identify an anomalous situation where the superradiance rate is temporarily increased by the reflection parameter R,which also occurs in the scalar scenario,but is largely magnified in vector condensates due to a faster growth rate in dominant mode.We point out that the condition for the growth anomaly in the adiabatic case is that information carried per particle exceeds a certain value δ1/δN>2πκ_(B)√(1+R)/(1-R).We further construct several featured quantities to illustrate it,and formalize the anomalyinduced gravitational wave strain deformation.
基金This work was supported by National Key Research and Development Program of China(Grant No.2017YFA0304303)the National Natu-ral Science Foundation of China(Grant No.11925404 and 11874235,11874342 and 11922411)+1 种基金Anhui Initiative in Quantum Information Technologies(AHY130200)a grant from the Institute for Guo Qiang(No.2019GQG1024),Tsinghua University.
文摘Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect quantum information against noise is vital for universal and scalable quantum computation.Among many different experimental platforms,superconducting quantum circuits and bosonic encodings in superconducting microwave modes are appealing for their unprecedented potential in QEC.During the last few years,bosonic QEC is demonstrated to reach the break-even point,i.e.the lifetime of a logical qubit is enhanced to exceed that of any individual components composing the experimental system.Beyond that,universal gate sets and fault-tolerant operations on the bosonic codes are also realized,pushing quantum information processing towards the QEC era.In this article,we review the recent progress of the bosonic codes,including the Gottesman-Kitaev-Preskill codes,cat codes,and binomial codes,and discuss the opportunities of bosonic codes in various quantum applications,ranging from fault-tolerant quantum computation to quantum metrology.We also summarize the challenges associated with the bosonic codes and provide an outlook for the potential research directions in the long terms.
基金support from the ARO (W911NF-18-1-0020 and W911NF-18-1-0212)ARO MURI (W911NF-16-1-0349)+3 种基金AFOSR MURI (FA9550-19-1-0399)NSF (EFMA-1640959, OMA-1936118, EEC-1941583)NTT Research, the Packard Foundation (201339273)the Startup Foundation of Institute of Semiconductors, Chinese Academy of Sciences (E0SEBB11)。
文摘Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible microwave-to-optical quantum transduction.There is emerging interest in utilizing bosonic modes for quantum information processing,with circuit quantum electrodynamics(circuit QED)as one of the leading architectures.Quantum information can be encoded into subspaces of a bosonic superconducting cavity mode with long coherence time.However,standard Gaussian operations(e.g.,beam splitting and two-mode squeezing)are insufficient for universal quantum computing.The major challenge is to introduce additional nonlinear control beyond Gaussian operations without adding significant bosonic loss or decoherence.Here we review recent advances in universal control of a single bosonic code with superconducting circuits,including unitary control,quantum feedback control,drivendissipative control and holonomic dissipative control.Various approaches to entangling different bosonic modes are also discussed.
基金Project supported by the National Natural Science Foundation of China (No. 10431040, No.10271047, No.19731004) the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institution of the Ministry of Education of China, the Specialized Research Fund for the Doctoral Program of Higher Education of the Ministry of Education of China, the Shanghai Rising-Star Program of the Science and Technology Commission of Shanghai and the Shanghai Priority Academic Discipline of the Education Commission of Shanghai.
文摘A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra Vir, a bosonic construction and the same decomposition for Vir are obtained.
基金partially supported by the National Key R&D Program of China (Grant No.2023YFA16067003)the National Science Foundation of China (Grant Nos.12435007 and 12522505)。
文摘We explore the potential of conducting an experiment in a low Earth orbit spacecraft and using the Earth as a spin and mass source to constrain beyond-the-standard-model(BSM)long-range spin-and velocity-dependent interactions,which are mediated by the exchange of an ultralight(m_(Z')<10^(-10)eV)or massless intermediate vector boson.The high speed of low-Earth-orbit spacecraft can enhance their sensitivity to velocity-dependent interactions.This periodicity enables efficient signal extraction from background noise,thereby improving the accuracy of the experiment.Combining these advantages,we theoretically demonstrate that the novel spacecraft-Earth model can improve the existing bounds on these exotic interactions by up to three orders of magnitude using the China Space Station(CSS)as a representative low-Earthorbit carrier.If successfully implemented,this model may provide an innovative strategy for detecting ultralight dark matter and yield tighter constraints on certain coupling constants of exotic interactions.
