The magnetic proximity effect enables interfacial modulation of excitonic and spin-valley properties in transition metal dichalcogenides(TMDs),offering a versatile route toward next-generation spintronic and valleytro...The magnetic proximity effect enables interfacial modulation of excitonic and spin-valley properties in transition metal dichalcogenides(TMDs),offering a versatile route toward next-generation spintronic and valleytronic devices.However,the inherently weak photoluminescence(PL)of bright excitons—suppressed by proximity-induced darkening mechanisms—hinders the optical detection of magnetic interactions.Here,we demonstrate substantial exciton emission enhancement in CrOCl/WSe_(2)(HS)and twisted 90°-CrOCl/CrOCl/WSe_(2)(THS)heterostructures by employing plasmonic Au nanopillar arrays to activate surface plasmon polariton(SPP)coupling.The neutral exciton emission intensity is enhanced by factors of 5 and 18 for HS/Au and THS/Au,respectively,with enhancements persisting under high magnetic fields and elevated temperatures(~10-fold in THS/Au).Enabled by this amplification,we observe pronounced Zeeman splitting and modified intervalley relaxation pathways,indicating significant magnetic proximity interactions.Finite-element simulations and first-principles calculations reveal that the enhancement arises from local electromagnetic field concentration and layer-dependent interfacial coupling.Our results establish SPP-assisted PL enhancement as an effective strategy for probing weak magneto-optical signatures,paving the way for detailed exploration of exciton-magnon coupling and interface-driven quantum phenomena in twodimensional(2D)magnetic heterostructures.展开更多
Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been ...Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been demonstrated in polariton condensates in III-V photonic crystal microcavities by condensing into a topological bound state in the continuum,offering a new light-matter hybrid platform for exploring such quantum phase.In this work,we propose a theoretical scheme for realizing room-temperature supersolidity based on halide perovskite exciton polaritons operating in the optical parametric oscillation regime.By employing a waveguide microcavity geometry,we confine polariton scattering direction in reciprocal space,enabling controlled momentum selection.Leveraging the intrinsic nonlinear interactions among polaritons,we theoretically demonstrate the spontaneous breaking of both continuous translational symmetry and global phase symmetry,i.e.,the evidence of supersolidity.Furthermore,we identify a tunable phase transition sequence in our system:from a Bose-Einstein condensate to a supersolid phase,and ultimately to an insulating phase,as the nonlinear interaction strength increases.展开更多
Surface plasmon polaritons(SPPs)on metal surfaces excited by p-polarized light have long been a crucial method for achieving lightmatter interactions due to their small mode-field volumes and strong optical localizati...Surface plasmon polaritons(SPPs)on metal surfaces excited by p-polarized light have long been a crucial method for achieving lightmatter interactions due to their small mode-field volumes and strong optical localization properties.However,the significant losses generated in metals greatly limit the intensity of the SPPs and their potential application scenarios.In this paper,we leverage the high refractive index properties of two-dimensional(2D)transition metal dichalcogenides(TMDCs)to generate transverse-electric(TE)polarized waves excited by s-polarized light on the surface of gold nanofilms by accurately controlling the number of the TMDC layers and the spatial refractive index variations with the structure.Unlike the SPPs excited by p-polarized light,the TE surface waves on the surface of the gold film exhibit low loss and high quality factor(Q factor).Moreover,the difference in refractive index causes the TE surface waves to be electromagnetically separated in space,lifting the electric field component in the excited TE surface waves from the surface of the metal film into the TMDCs,thereby minimizing the ohmic loss in the metal and enabling strong coupling between the TE surface waves and the two-exciton states(A-exciton and B-exciton)in the TMDCs.Experimental results demonstrated the strong coupling of TE waves with double excitons(A-exciton and B-exciton)in multilayer MoS_(2) by exciting the Au/MoS_(2) heterostructure using a KretschmannRaether configuration,showing ultrahigh Rabi splitting up to about 310 meV.Furthermore,the number of MoS_(2) layers can be accurately determined by measuring the redshift of the Rabi splitting peak of the strong coupling spectra in the Au/MoS_(2) heterostructure.Our findings open a new avenue for manipulating strong exciton-photon coupling in 2D materials and offer a novel approach for accurately characterizing the thickness of TMDCs.展开更多
Negative friction refers to a frictional force that acts in the same direction as the motion of an object, which has been predicted in terahertz(THz) gain systems [Phys. Rev. B 108 045406(2023)]. In this work, we inve...Negative friction refers to a frictional force that acts in the same direction as the motion of an object, which has been predicted in terahertz(THz) gain systems [Phys. Rev. B 108 045406(2023)]. In this work, we investigate the enhancement of the negative friction experienced by nanospheres placed near a graphene substrate. We find that the magnitude of negative friction is related to the resonant coupling between the surface plasmon polaritons(SPPs) of the graphene and localized surface phonon polaritons(LSPh P) of nanospheres. We exam nanospheres consisted of several different materials, including SiO_(2), Si C, Zn Se, Na Cl, ln Sb. Our results suggest that the LSPh P of Na Cl nanospheres match effectively with the amplified SPPs of graphene sheets. The negative friction for Na Cl nanospheres can be enhanced about one-to-two orders of magnitude compared to that of silica(SiO_(2)) nanospheres. At the resonant peak of negative friction, the required quasi-Fermi energy of graphene is lower for Na Cl nanospheres. Our finds hold great prospects for the mechanical manipulations of nanoscale particles.展开更多
Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in ...Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in Ⅲ-Ⅴ semiconductors at liquid helium temperatures.However,the complex fabrication of these microcavities and operating temperatures limit their room-temperature practical application.Here,we experimentally realize room-temperature exciton-polariton condensation and polaritonic lasing in a CsPbBr_(3)perovskite planar microcavity fabricated by the pressing process.Angleresolved photoluminescence spectra demonstrate the strong light-matter coupling and the formation of exciton-polaritons in such a pressed microcavity.Above the critical threshold,mass polaritons accumulating at the bottom of dispersion lead to a narrow emission linewidth and pronounced blueshift,further reinforcing the Bose-Einstein condensation and polaritonic lasing in this system.Our results offer a feasible and effective approach to investigate exciton-polariton condensation and polariton lasing at room temperature.展开更多
Two-dimensional(2D)transition-metal dichalcogenide(TMD)monolayers based on become a promising platform to study photonics and optoelectronics.Electrically controlling the excitonic properties of TMD monolayers can be ...Two-dimensional(2D)transition-metal dichalcogenide(TMD)monolayers based on become a promising platform to study photonics and optoelectronics.Electrically controlling the excitonic properties of TMD monolayers can be realized in different devices.In this work,we realize the strong coupling between the excitons of WS_(2)monolayers and a photonic cavity mode in a liquid crystal microcavity.The formed exciton polaritons can be electrically tuned by applying voltage to the microcavity.Our work offers a way to study exciton-polariton manipulation based on TMD monolayers by electrical methods at room temperature.展开更多
Accurate and real-time detection of hydrogen(H_(2))is essential for ensuring energy security.Fiber-optic H_(2) sensors are gaining attention for their integration and remote sensing capabilities.However,they face chal...Accurate and real-time detection of hydrogen(H_(2))is essential for ensuring energy security.Fiber-optic H_(2) sensors are gaining attention for their integration and remote sensing capabilities.However,they face challenges,including complex fabrication processes and limited response times.Here,we propose a fiber-optic H_(2) sensing tip based on Tamm plasmon polariton(TPP)resonance,consisting of a multilayer metal/dielectric Bragg reflector deposited directly on the fiber end facet,simplifying the fabrication process.The fiber-optic TPP(FOTPP)tip exhibits both TPP and multiple Fabry-Perot(FP)resonances simultaneously,with the TPP employed for highly sensitive H_(2) detection.Compared to FP resonance,TPP exhibits more than twice the sensitivity under the same structural dimension without cavity geometry deformation.The excellent performance is attributed to alterations in phase-matching conditions,driven by changes in penetration depth of TPP.Furthermore,the FP mode is utilized to achieve an efficient photothermal effect to catalyze the reaction between H_(2) and the FOTPP structure.Consequently,the response and recovery speeds of the FOTPP tip under resonance-enhanced photothermal assistance are improved by 6.5 and 2.1 times,respectively.Our work offers a novel strategy for developing TPP-integrated fiber-optic tips,refines the theoretical framework of photothermal-assisted detection systems,and provides clear experimental evidence.展开更多
We investigate nonreciprocal transmission in microcavity exciton polaritons and obtain analytical conditions for achieving unidirectional and circular transmission.The phase difference between two effective optomechan...We investigate nonreciprocal transmission in microcavity exciton polaritons and obtain analytical conditions for achieving unidirectional and circular transmission.The phase difference between two effective optomechanical couplings can regulate the interference of different channels between two photon modes,and control the direction of nonreciprocity,resulting in unidirectional forward and backward transmissions.Perfect nonreciprocal unidirectional transmission with zero losses is realized,which depends on exciton-photon-phonon couplings.Moreover,clockwise and counterclockwise circular transmissions are implemented by appropriately adjusting the phase of photon mode couplings.Our results open up exciting possibilities for implementing nonreciprocal photonic devices.展开更多
A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication chan...A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.展开更多
In this paper,we report the exciton polaritons in both positive and negative detuning micro cavities based on InGaN multi-quantum wells(MQWs)and the first polariton lasing in InGaN/GaN MQWs at room temperature by util...In this paper,we report the exciton polaritons in both positive and negative detuning micro cavities based on InGaN multi-quantum wells(MQWs)and the first polariton lasing in InGaN/GaN MQWs at room temperature by utilizing a 4.5λFabry-Perot(F-P)cavity with double dielectric distributed Bragg reflectors(DBRs).Double thresholds corresponding respectively to polariton lasing and photonic lasing are observed along with half-width narrowing and peak blue-shifts.The threshold of polariton lasing is about half of the threshold of photonic lasing.Our results paved a substantial way for ultra-low threshold lasers and room temperature Bose-Einstein Condensate(BEC)in nitride semiconductors.展开更多
A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) fil...A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) film and a silver rectangle block. The generation efficiency of this SPPs generator is investigated using the finite difference time domain method. Due to the presence of the silver rectangle block, the SPPs generation efficiency of the asymmetric single nanoslit with PVA film can be greatly enhanced and the corresponding wavelength with the maximum enhancement factor can be tuned flexibly. The influence of the structural parameters on the generation efficiency is also investigated for the enhanced unidirectional SPPs generator.展开更多
As the combination of surface plasmon polariton and femtosecond laser pulse,femtosecond surface plasmon polariton has both nanoscale spatial resolution and femtosecond temporal resolution,and thus provides promising m...As the combination of surface plasmon polariton and femtosecond laser pulse,femtosecond surface plasmon polariton has both nanoscale spatial resolution and femtosecond temporal resolution,and thus provides promising methods for light field manipulation and light-matter interaction in extreme small spatiotemporal scales.Nowadays,the research on femtosecond surface plasmon polariton is mainly concentrated on two aspects:one is investigation and characterization of excitation,propagation,and dispersion properties of femtosecond surface plasmon polariton in different structures or materials;the other one is developing new applications based on its unique properties in the fields of nonlinear enhancement,pulse shaping,spatiotemporal super-resolved imaging,and others.Here,we introduce the research progress of properties and applications of femtosecond surface plasmon polariton,and prospect its future research trends.With the further development of femtosecond surface plasmon polariton research,it will have a profound impact on nano-optoelectronics,molecular dynamics,biomedicine and other fields.展开更多
Surface plasmon polaritons excited by an electron beam can be transformed into coherent and tunable light radiation waves with power enhancement in the simple structure of a metal film with a dielectric medium loading...Surface plasmon polaritons excited by an electron beam can be transformed into coherent and tunable light radiation waves with power enhancement in the simple structure of a metal film with a dielectric medium loading. In this paper, the process of the radiation transformation of this radiation, and the dependencies of the radiation characteristics on the parameters of the structure and the electron beam are studied in detail. The radiation power enhancement is greatly influenced by the beam energy and the film thickness in the infrared to ultraviolet frequency region. Up to 122 times radiation power enhancement and 6.5% radiation frequency tuning band can be obtained by optimizing the beam energy and the parameters of the film.展开更多
We theoretically investigate the control of surface plasmon polariton（SPP） generated at the interface of dielectric and graphene medium under Kerr nonlinearity. The controlled Kerr nonlinear signal of probe light be...We theoretically investigate the control of surface plasmon polariton（SPP） generated at the interface of dielectric and graphene medium under Kerr nonlinearity. The controlled Kerr nonlinear signal of probe light beam in a dielectric medium is used to generate SPPs at the interface of dielectric and graphene medium. The positive, negative absorption, and dispersion properties of SPPs are modified and controlled by the control and Kerr fields. A large amplification（negative absorption） is noted for SPPs under the Kerr nonlinearity. The normal/anomalous slope of dispersion and propagation length of SPPs is modified and controlled with Kerr nonlinearity. This leads to significant variation in slow and fast SPP propagation. The controlled slow and fast SPP propagation may predict significant applications in nano-photonics, optical tweezers, photovoltaic devices, plasmonster, and sensing technology.展开更多
A new type of cavity polariton,the optical Tamm state（OTS） polariton,is proposed to be realized by sandwiching a quantum well（QW） between a gold layer and a distributed Bragg reflector（DBR）.It is shown that OTS ...A new type of cavity polariton,the optical Tamm state（OTS） polariton,is proposed to be realized by sandwiching a quantum well（QW） between a gold layer and a distributed Bragg reflector（DBR）.It is shown that OTS polaritons can be generated from the strong couplings between the QW excitons and the free OTSs.In addition,if a second gold layer is introduced into the bottom of the DBR,two independent free OTSs can interact strongly with the QW excitons to produce extra OTS polaritons.展开更多
We analyze the electromagnetic interaction between local surface plasmon polaritons （SPPs） and an atmospheric surface wave plasma jet （ASWPJ） in combination with our designed discharge device. Before discharge, th...We analyze the electromagnetic interaction between local surface plasmon polaritons （SPPs） and an atmospheric surface wave plasma jet （ASWPJ） in combination with our designed discharge device. Before discharge, the excitation of the SPPs and the spatial distribution of the enhanced electric field are analyzed. During discharge, the critical breakdown electric field of the gases at atmospheric gas pressure and the surface wave of the SPPs converted into electron plasma waves at resonant points are studied. After discharge, the ionization development process of the ASWPJ is simulated using a two- dimensional fluid model. Our results suggest that the local enhanced electric field of SPPs is merely the precondition of gas breakdown, and the key mechanism in maintaining the discharge development of a low-power ASWPJ is the wave-mode conversion of the local enhanced electric field at the resonant point.展开更多
Long-range surface plasmon polariton （LRSPP） modes in an asymmetrical system, in which the thin metal film is sandwiched between a semi-infinite substrate and a high permittivity polymer film with a finite thickness...Long-range surface plasmon polariton （LRSPP） modes in an asymmetrical system, in which the thin metal film is sandwiched between a semi-infinite substrate and a high permittivity polymer film with a finite thickness, are theoret~ ically calculated and analyzed. Due to the high permittivity of the polymer film, at proper polymer film thicknesses, the index-matching condition of the dielectrics at both sides of the metal can be satisfied for supporting LRSPP modes, and the electromagnetic field above the metal can be localized well. It is found that these LRSPP modes have both long propagation lengths and subwavelength mode expansion above the metal at the optimal polymer film thickncsses. Furthermore, the requirements on the refractive index and the thickness of the polymer film to support LRSPP modes at the optimal thicknesses are found to be not critical.展开更多
Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger wid...Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger width of strip is required to load deeper grooves,which is cumbersome in modern large-scale integrated circuits and chips.In this work,a new spoof SPP transmission line (TL) with zigzag grooves is proposed.This new structure can achieve stronger field confinement compared to conventional one with the same strip width.In other words,the proposed spoof SPP TL behaves equivalently to a conventional one with much larger size.Dispersion analysis theoretically indicates the negative correlation between the ability of field confinement and cutoff frequencies of spoof SPP TLs.Numerical simulations indicate that the cutoff frequency of the proposed TL is lower than the conventional one and can be easily modified with the fixed size.Furthermore,two samples of the new and conventional spoof SPP TLs are fabricated for experimental demonstration.Measured S-parameters and field distributions verify the ultra-strong ability of field confinement of the proposed spoof SPP TL.Hence,this novel spoof SPP structure with ultra-strong field confinement may find wide applications in microwave and terahertz engineering.展开更多
We present a detailed analysis on mode evolution of gratingcoupled surface plasmonic polaritons （SPPs） on a conical metal tip based on the guidedwave theory. The eigenvalue equations for SPPs modes are discussed, re...We present a detailed analysis on mode evolution of gratingcoupled surface plasmonic polaritons （SPPs） on a conical metal tip based on the guidedwave theory. The eigenvalue equations for SPPs modes are discussed, revealing that cylindrical metal waveguides only support TM01 and HEm1 surface modes. During propagation on the metal tip, the gratingcoupled SPPs are converted to HE31, HE21, HE11 and TM01 successively, and these modes are sequentially cut off except TM01. The TM01 mode further propagates with drastically increasing effective mode index and is converted to localized surface plasmons （LSPs） at the tip apex, which is responsible for plasmonic nanofocusing. The gapmode plasmons can be excited with the focusing TM01 mode by approaching a metal substrate to the tip apex, resulting in further enhanced electric field and reduced size of the plasmonic focus.展开更多
基金the National Natural Science Foundation of China(No.52373311)the Innovation Program for Quantum Science and Technology(No.2021ZD0301605)+3 种基金provided by the National Natural Science Foundation of China(Nos.92263202 and 12374020)the National Key Research and Development Program of China(No.2020YFA0711502)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)support from the Australian Research Council(ARC Discovery Project,No.DP180102976).
文摘The magnetic proximity effect enables interfacial modulation of excitonic and spin-valley properties in transition metal dichalcogenides(TMDs),offering a versatile route toward next-generation spintronic and valleytronic devices.However,the inherently weak photoluminescence(PL)of bright excitons—suppressed by proximity-induced darkening mechanisms—hinders the optical detection of magnetic interactions.Here,we demonstrate substantial exciton emission enhancement in CrOCl/WSe_(2)(HS)and twisted 90°-CrOCl/CrOCl/WSe_(2)(THS)heterostructures by employing plasmonic Au nanopillar arrays to activate surface plasmon polariton(SPP)coupling.The neutral exciton emission intensity is enhanced by factors of 5 and 18 for HS/Au and THS/Au,respectively,with enhancements persisting under high magnetic fields and elevated temperatures(~10-fold in THS/Au).Enabled by this amplification,we observe pronounced Zeeman splitting and modified intervalley relaxation pathways,indicating significant magnetic proximity interactions.Finite-element simulations and first-principles calculations reveal that the enhancement arises from local electromagnetic field concentration and layer-dependent interfacial coupling.Our results establish SPP-assisted PL enhancement as an effective strategy for probing weak magneto-optical signatures,paving the way for detailed exploration of exciton-magnon coupling and interface-driven quantum phenomena in twodimensional(2D)magnetic heterostructures.
基金supported by the National Natural Science Foundation of China(Grant No.12434011 obtained by Q X)the China Postdoctoral Science Foundation(Grant No.Y24PJ2425214 obtained by L T).
文摘Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been demonstrated in polariton condensates in III-V photonic crystal microcavities by condensing into a topological bound state in the continuum,offering a new light-matter hybrid platform for exploring such quantum phase.In this work,we propose a theoretical scheme for realizing room-temperature supersolidity based on halide perovskite exciton polaritons operating in the optical parametric oscillation regime.By employing a waveguide microcavity geometry,we confine polariton scattering direction in reciprocal space,enabling controlled momentum selection.Leveraging the intrinsic nonlinear interactions among polaritons,we theoretically demonstrate the spontaneous breaking of both continuous translational symmetry and global phase symmetry,i.e.,the evidence of supersolidity.Furthermore,we identify a tunable phase transition sequence in our system:from a Bose-Einstein condensate to a supersolid phase,and ultimately to an insulating phase,as the nonlinear interaction strength increases.
基金Natural Science Foundation of Guangdong Province(2025A1515012259)National Natural Science Foundation of China(12274148,12374347,12174123).
文摘Surface plasmon polaritons(SPPs)on metal surfaces excited by p-polarized light have long been a crucial method for achieving lightmatter interactions due to their small mode-field volumes and strong optical localization properties.However,the significant losses generated in metals greatly limit the intensity of the SPPs and their potential application scenarios.In this paper,we leverage the high refractive index properties of two-dimensional(2D)transition metal dichalcogenides(TMDCs)to generate transverse-electric(TE)polarized waves excited by s-polarized light on the surface of gold nanofilms by accurately controlling the number of the TMDC layers and the spatial refractive index variations with the structure.Unlike the SPPs excited by p-polarized light,the TE surface waves on the surface of the gold film exhibit low loss and high quality factor(Q factor).Moreover,the difference in refractive index causes the TE surface waves to be electromagnetically separated in space,lifting the electric field component in the excited TE surface waves from the surface of the metal film into the TMDCs,thereby minimizing the ohmic loss in the metal and enabling strong coupling between the TE surface waves and the two-exciton states(A-exciton and B-exciton)in the TMDCs.Experimental results demonstrated the strong coupling of TE waves with double excitons(A-exciton and B-exciton)in multilayer MoS_(2) by exciting the Au/MoS_(2) heterostructure using a KretschmannRaether configuration,showing ultrahigh Rabi splitting up to about 310 meV.Furthermore,the number of MoS_(2) layers can be accurately determined by measuring the redshift of the Rabi splitting peak of the strong coupling spectra in the Au/MoS_(2) heterostructure.Our findings open a new avenue for manipulating strong exciton-photon coupling in 2D materials and offer a novel approach for accurately characterizing the thickness of TMDCs.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11804288)the Key Scientific Research Project of Higher Education Institutions in Henan Province, China (Grant No. 20231205164502999)。
文摘Negative friction refers to a frictional force that acts in the same direction as the motion of an object, which has been predicted in terahertz(THz) gain systems [Phys. Rev. B 108 045406(2023)]. In this work, we investigate the enhancement of the negative friction experienced by nanospheres placed near a graphene substrate. We find that the magnitude of negative friction is related to the resonant coupling between the surface plasmon polaritons(SPPs) of the graphene and localized surface phonon polaritons(LSPh P) of nanospheres. We exam nanospheres consisted of several different materials, including SiO_(2), Si C, Zn Se, Na Cl, ln Sb. Our results suggest that the LSPh P of Na Cl nanospheres match effectively with the amplified SPPs of graphene sheets. The negative friction for Na Cl nanospheres can be enhanced about one-to-two orders of magnitude compared to that of silica(SiO_(2)) nanospheres. At the resonant peak of negative friction, the required quasi-Fermi energy of graphene is lower for Na Cl nanospheres. Our finds hold great prospects for the mechanical manipulations of nanoscale particles.
基金support from theNational Natural Science Foundation(Grant No.12204111)the National Key Research and Development Program ofChina(Grant No.2023YFA1407100)Shanghai Pilot Pro-gram for Basic Research(Grant No.22JC1403202)。
文摘Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in Ⅲ-Ⅴ semiconductors at liquid helium temperatures.However,the complex fabrication of these microcavities and operating temperatures limit their room-temperature practical application.Here,we experimentally realize room-temperature exciton-polariton condensation and polaritonic lasing in a CsPbBr_(3)perovskite planar microcavity fabricated by the pressing process.Angleresolved photoluminescence spectra demonstrate the strong light-matter coupling and the formation of exciton-polaritons in such a pressed microcavity.Above the critical threshold,mass polaritons accumulating at the bottom of dispersion lead to a narrow emission linewidth and pronounced blueshift,further reinforcing the Bose-Einstein condensation and polaritonic lasing in this system.Our results offer a feasible and effective approach to investigate exciton-polariton condensation and polariton lasing at room temperature.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174285 and 12474315)support from the National Natural Science Foundation of China(Grant No.62375200)+2 种基金support from the National Natural Science Foundation of China(Grant No.12504372)the China Postdoctoral Science Foundation-Tianjin Joint Support Program(Grant No.2025T003TJ)support from the National Natural Science Foundation of China(Grant No.12404424)。
文摘Two-dimensional(2D)transition-metal dichalcogenide(TMD)monolayers based on become a promising platform to study photonics and optoelectronics.Electrically controlling the excitonic properties of TMD monolayers can be realized in different devices.In this work,we realize the strong coupling between the excitons of WS_(2)monolayers and a photonic cavity mode in a liquid crystal microcavity.The formed exciton polaritons can be electrically tuned by applying voltage to the microcavity.Our work offers a way to study exciton-polariton manipulation based on TMD monolayers by electrical methods at room temperature.
基金financial supports from National Key Research and Development Program of China(2023YFB3209500)National Natural Science Foundation of China(NSFC)(12274052 and 62171076)+1 种基金Fundamental Research Funds for the Central Universities(DUT24ZD203)Bolian Research Funds of Dalian Maritime University and Fundamental Research Funds for the Central Universities(3132024605).
文摘Accurate and real-time detection of hydrogen(H_(2))is essential for ensuring energy security.Fiber-optic H_(2) sensors are gaining attention for their integration and remote sensing capabilities.However,they face challenges,including complex fabrication processes and limited response times.Here,we propose a fiber-optic H_(2) sensing tip based on Tamm plasmon polariton(TPP)resonance,consisting of a multilayer metal/dielectric Bragg reflector deposited directly on the fiber end facet,simplifying the fabrication process.The fiber-optic TPP(FOTPP)tip exhibits both TPP and multiple Fabry-Perot(FP)resonances simultaneously,with the TPP employed for highly sensitive H_(2) detection.Compared to FP resonance,TPP exhibits more than twice the sensitivity under the same structural dimension without cavity geometry deformation.The excellent performance is attributed to alterations in phase-matching conditions,driven by changes in penetration depth of TPP.Furthermore,the FP mode is utilized to achieve an efficient photothermal effect to catalyze the reaction between H_(2) and the FOTPP structure.Consequently,the response and recovery speeds of the FOTPP tip under resonance-enhanced photothermal assistance are improved by 6.5 and 2.1 times,respectively.Our work offers a novel strategy for developing TPP-integrated fiber-optic tips,refines the theoretical framework of photothermal-assisted detection systems,and provides clear experimental evidence.
基金supported by the National Natural Science Foundation of China(Grant Nos.12104374,12164042,and 12264045)the Natural Science Foundation of Gansu Province,China(Grant No.20JR5RA526).
文摘We investigate nonreciprocal transmission in microcavity exciton polaritons and obtain analytical conditions for achieving unidirectional and circular transmission.The phase difference between two effective optomechanical couplings can regulate the interference of different channels between two photon modes,and control the direction of nonreciprocity,resulting in unidirectional forward and backward transmissions.Perfect nonreciprocal unidirectional transmission with zero losses is realized,which depends on exciton-photon-phonon couplings.Moreover,clockwise and counterclockwise circular transmissions are implemented by appropriately adjusting the phase of photon mode couplings.Our results open up exciting possibilities for implementing nonreciprocal photonic devices.
基金supported in part by the Natural Science Foundation of Tianjin(No.19JCYBJC16100)the Tianjin Innovation and Entrepreneurship Training Program(No.202210060027)。
文摘A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.
基金National Key Research and Development Program of China(No.2016YFB0400803)the Science Challenge Project(No.TZ2016003)the National Natural Science Foundation of China(Nos.61704140,U1505253).
文摘In this paper,we report the exciton polaritons in both positive and negative detuning micro cavities based on InGaN multi-quantum wells(MQWs)and the first polariton lasing in InGaN/GaN MQWs at room temperature by utilizing a 4.5λFabry-Perot(F-P)cavity with double dielectric distributed Bragg reflectors(DBRs).Double thresholds corresponding respectively to polariton lasing and photonic lasing are observed along with half-width narrowing and peak blue-shifts.The threshold of polariton lasing is about half of the threshold of photonic lasing.Our results paved a substantial way for ultra-low threshold lasers and room temperature Bose-Einstein Condensate(BEC)in nitride semiconductors.
基金Project supported by the National Natural Science Foundation of China （Grant Nos. 11174237 and 10974161）, the National Basic Research Program of China （Grant No. 2013CB328904）, the Fundamental Research Funds for the Central Universities of Ministry of Education of China （Grant Nos. SWJTU 12CX084 and SWJTU2（/10ZT06）, and the Innovation Fund for Ph.D. Student of Southwest Jiaotong University, China.
文摘A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) film and a silver rectangle block. The generation efficiency of this SPPs generator is investigated using the finite difference time domain method. Due to the presence of the silver rectangle block, the SPPs generation efficiency of the asymmetric single nanoslit with PVA film can be greatly enhanced and the corresponding wavelength with the maximum enhancement factor can be tuned flexibly. The influence of the structural parameters on the generation efficiency is also investigated for the enhanced unidirectional SPPs generator.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91750205,61427819,U1701661,11674178,and 61975128)the Leading Talents of Guangdong Province Program,China(Grant No.00201505)+2 种基金the Natural Science Foundation of Guangdong Province,China(Grant Nos.2016A030312010 and 2017A030313351)the Science and Technology Innovation Commission of Shenzhen City(Grant Nos.JCYJ20180507182035270,KQTD2017033011044403,KQJSCX20170727100838364,ZDSYS201703031605029,and JCYJ2017818144338999)the K.C.Wong Education Foundation(Grant No.GJTD-2018-08)。
文摘As the combination of surface plasmon polariton and femtosecond laser pulse,femtosecond surface plasmon polariton has both nanoscale spatial resolution and femtosecond temporal resolution,and thus provides promising methods for light field manipulation and light-matter interaction in extreme small spatiotemporal scales.Nowadays,the research on femtosecond surface plasmon polariton is mainly concentrated on two aspects:one is investigation and characterization of excitation,propagation,and dispersion properties of femtosecond surface plasmon polariton in different structures or materials;the other one is developing new applications based on its unique properties in the fields of nonlinear enhancement,pulse shaping,spatiotemporal super-resolved imaging,and others.Here,we introduce the research progress of properties and applications of femtosecond surface plasmon polariton,and prospect its future research trends.With the further development of femtosecond surface plasmon polariton research,it will have a profound impact on nano-optoelectronics,molecular dynamics,biomedicine and other fields.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB339801)the National Natural Science Foundation of China(Grant Nos.61231005,11305030,and 612111076)the National High Technology Research and Development Program of China(Grant No.2011AA010204)
文摘Surface plasmon polaritons excited by an electron beam can be transformed into coherent and tunable light radiation waves with power enhancement in the simple structure of a metal film with a dielectric medium loading. In this paper, the process of the radiation transformation of this radiation, and the dependencies of the radiation characteristics on the parameters of the structure and the electron beam are studied in detail. The radiation power enhancement is greatly influenced by the beam energy and the film thickness in the infrared to ultraviolet frequency region. Up to 122 times radiation power enhancement and 6.5% radiation frequency tuning band can be obtained by optimizing the beam energy and the parameters of the film.
文摘We theoretically investigate the control of surface plasmon polariton（SPP） generated at the interface of dielectric and graphene medium under Kerr nonlinearity. The controlled Kerr nonlinear signal of probe light beam in a dielectric medium is used to generate SPPs at the interface of dielectric and graphene medium. The positive, negative absorption, and dispersion properties of SPPs are modified and controlled by the control and Kerr fields. A large amplification（negative absorption） is noted for SPPs under the Kerr nonlinearity. The normal/anomalous slope of dispersion and propagation length of SPPs is modified and controlled with Kerr nonlinearity. This leads to significant variation in slow and fast SPP propagation. The controlled slow and fast SPP propagation may predict significant applications in nano-photonics, optical tweezers, photovoltaic devices, plasmonster, and sensing technology.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61106045)
文摘A new type of cavity polariton,the optical Tamm state（OTS） polariton,is proposed to be realized by sandwiching a quantum well（QW） between a gold layer and a distributed Bragg reflector（DBR）.It is shown that OTS polaritons can be generated from the strong couplings between the QW excitons and the free OTSs.In addition,if a second gold layer is introduced into the bottom of the DBR,two independent free OTSs can interact strongly with the QW excitons to produce extra OTS polaritons.
基金Project supported by the National Natural Science Foundation of China(Grant No.11105002)the Open-end Fund of State Key Laboratory of Structural Analysis for Industrial Equipment,China(Grant No.GZ1215)+1 种基金the Natural Science Foundation for University in Anhui Province of China(Grant No.KJ2013A106)the Doctoral Scientific Research Funds of Anhui University of Science and Technology,China
文摘We analyze the electromagnetic interaction between local surface plasmon polaritons （SPPs） and an atmospheric surface wave plasma jet （ASWPJ） in combination with our designed discharge device. Before discharge, the excitation of the SPPs and the spatial distribution of the enhanced electric field are analyzed. During discharge, the critical breakdown electric field of the gases at atmospheric gas pressure and the surface wave of the SPPs converted into electron plasma waves at resonant points are studied. After discharge, the ionization development process of the ASWPJ is simulated using a two- dimensional fluid model. Our results suggest that the local enhanced electric field of SPPs is merely the precondition of gas breakdown, and the key mechanism in maintaining the discharge development of a low-power ASWPJ is the wave-mode conversion of the local enhanced electric field at the resonant point.
基金supported by the National Natural Science Foundation of China (Grant Nos 10434020,10821062 and 10804004)the State Key Development Program for Basic Research of China (Grant Nos 2007CB307001 and 2009CB930504)the Research Fund for the Doctoral Program of Higher Education of China (Grant No 200800011023)
文摘Long-range surface plasmon polariton （LRSPP） modes in an asymmetrical system, in which the thin metal film is sandwiched between a semi-infinite substrate and a high permittivity polymer film with a finite thickness, are theoret~ ically calculated and analyzed. Due to the high permittivity of the polymer film, at proper polymer film thicknesses, the index-matching condition of the dielectrics at both sides of the metal can be satisfied for supporting LRSPP modes, and the electromagnetic field above the metal can be localized well. It is found that these LRSPP modes have both long propagation lengths and subwavelength mode expansion above the metal at the optimal polymer film thickncsses. Furthermore, the requirements on the refractive index and the thickness of the polymer film to support LRSPP modes at the optimal thicknesses are found to be not critical.
基金the National Natural Science Foundation of China under Grant Nos.61871127,61701246,61631007,61571117,61501112,61501117,61522106,61722106,61701107,and 61701108,and 111 Project under Grant No.111-2-05.
文摘Ultrathin corrugated metallic structures have been proved to support spoof surface plasmon polariton (SPP) modes on two-dimension (2D) planar microwave circuits.However,to provide stronger field confinement,larger width of strip is required to load deeper grooves,which is cumbersome in modern large-scale integrated circuits and chips.In this work,a new spoof SPP transmission line (TL) with zigzag grooves is proposed.This new structure can achieve stronger field confinement compared to conventional one with the same strip width.In other words,the proposed spoof SPP TL behaves equivalently to a conventional one with much larger size.Dispersion analysis theoretically indicates the negative correlation between the ability of field confinement and cutoff frequencies of spoof SPP TLs.Numerical simulations indicate that the cutoff frequency of the proposed TL is lower than the conventional one and can be easily modified with the fixed size.Furthermore,two samples of the new and conventional spoof SPP TLs are fabricated for experimental demonstration.Measured S-parameters and field distributions verify the ultra-strong ability of field confinement of the proposed spoof SPP TL.Hence,this novel spoof SPP structure with ultra-strong field confinement may find wide applications in microwave and terahertz engineering.
基金This work was financially supported by the National Natural Science Foundation of China （NSFC） （61675169, 61377055 and 11634010）, the National Key R＆D Program of China （2017YFA0303800）, and the Fundamental Research Funds for the Central Universities （3102017zy021, 3102017HQZZ 022）.
文摘We present a detailed analysis on mode evolution of gratingcoupled surface plasmonic polaritons （SPPs） on a conical metal tip based on the guidedwave theory. The eigenvalue equations for SPPs modes are discussed, revealing that cylindrical metal waveguides only support TM01 and HEm1 surface modes. During propagation on the metal tip, the gratingcoupled SPPs are converted to HE31, HE21, HE11 and TM01 successively, and these modes are sequentially cut off except TM01. The TM01 mode further propagates with drastically increasing effective mode index and is converted to localized surface plasmons （LSPs） at the tip apex, which is responsible for plasmonic nanofocusing. The gapmode plasmons can be excited with the focusing TM01 mode by approaching a metal substrate to the tip apex, resulting in further enhanced electric field and reduced size of the plasmonic focus.
