The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four ...The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.展开更多
Photon scattering properties in one-dimensional waveguide side coupled to a nanocavity embedded in two atoms with dipole-dipole interaction （DDI） are investigated theoretically. The analytical expressions of the tra...Photon scattering properties in one-dimensional waveguide side coupled to a nanocavity embedded in two atoms with dipole-dipole interaction （DDI） are investigated theoretically. The analytical expressions of the transmission and reflection amplitudes are deduced by using the real-space Hamiltonian. A method to determine the coupling strength of DDI is proposed. Realization of single photon switching by modulation the DDI is investigated. The influence of dissipations on the performance of the single photon switching are exhibited. An asymmetric Fano-type resonance, which can be controlled by the DDI, appears in the transmission spectrum.展开更多
We theoretically investigate single-photon polarization conversion via scattering by an atom with Λ configuration coupled to a semi-infinite waveguide and discuss the two cases in which the Λ system is non-degenerat...We theoretically investigate single-photon polarization conversion via scattering by an atom with Λ configuration coupled to a semi-infinite waveguide and discuss the two cases in which the Λ system is non-degenerated and degenerated. By applying the hard-wall boundary condition of the semi-infinite waveguide, it is found that singlephoton polarization conversion can be realized with unit probability for both cases under the ideal condition.Together with the polarization conversion, the frequency conversion of a single photon can also be realized with unit probability in the ideal case if the Λ system is not degenerated.展开更多
Atom–nanowire coupling system is a promising platform for optical quantum information processing. Unlike the previous designing of optical switch and transistor requiring a dedicated multi-level emitter and high fine...Atom–nanowire coupling system is a promising platform for optical quantum information processing. Unlike the previous designing of optical switch and transistor requiring a dedicated multi-level emitter and high fineness microcavity,a new proposal is put forward which contains a single two-level atom asymmetrically coupled with two nanowires. Singleemitter manipulation of photonic signals for bilateral coherent incident is clear now, since we specify atomic saturation nonlinearity into three contributions which brings us a new approach to realizing light-controlled-light at weak light and single-atom levels. An efficient optically controllable switch based on self-matching-induced-block and a concise optical transistor are proposed. Our findings show potential applications in full-optical devices.展开更多
We investigate theoretically the population dynamics and the second-order correlation functions of photon emissions from the biexciton-exciton system of a single quantum dot with excitation from pulses to continuous w...We investigate theoretically the population dynamics and the second-order correlation functions of photon emissions from the biexciton-exciton system of a single quantum dot with excitation from pulses to continuous wave. The dynamic equations of the correlation functions are deduced by applying quantum regression theorem to optical Bloch equations. The influences of excitation pulse width on the correlation function have been discussed in detail.展开更多
We theoretically design a single-mode plasmonic ring nanocavity. Based on the plasmonic cavity, the exciton dynamics between two identical quantum dots （QD-p, QD-q） coupled to the nanocavity are investigated. It is ...We theoretically design a single-mode plasmonic ring nanocavity. Based on the plasmonic cavity, the exciton dynamics between two identical quantum dots （QD-p, QD-q） coupled to the nanocavity are investigated. It is shown that the coupling factors gi （i = p, q） between QD-i and surface plasmons are both equal to 12.53meV in our model and exeiton population swap between the two QDs can be realized. The periods and amplitudes of population oscillations can be modified by the coupling factors. Our results may have potential applications in quantum information and quantum computation on a chip.展开更多
Coherent perfect absorption provides a method of light-controlling-light and has practical applications in optical communications. Recently, a cavity-based nonlinear perfect photon absorption extends the coherent perf...Coherent perfect absorption provides a method of light-controlling-light and has practical applications in optical communications. Recently, a cavity-based nonlinear perfect photon absorption extends the coherent perfect absorber（CPA）beyond the linear regime. As nanowire-based system is a more competitive candidate for full-optical device, we introduce a nonlinear CPA in the single two-level atom–nanowires coupling system in this work. Nonlinear input–output relations are derived analytically, and three contributions of atomic saturation nonlinearity are explicit. The consociation of optical nonlinearity and destructive interference makes it feasible to fabricate a nonlinear monoatomic CPA. Our results also indicate that a nonlinear system may work linearly even when the incoming lights are not weak any more. Our findings show promising applications in full-optical devices.展开更多
We investigate theoretically single photon transport in one-dimensional waveguide coupled to a pair of cavities,which are denoted by the first cavity and the auxiliary cavity.Two cases with no atom and one atom embedd...We investigate theoretically single photon transport in one-dimensional waveguide coupled to a pair of cavities,which are denoted by the first cavity and the auxiliary cavity.Two cases with no atom and one atom embedded in the first cavity are discussed.The Fano dips in the transmission spectrum and locations of transparency window are calculated.When no atom is embedded in the first cavity,there exists a transparency window under the condition that the first cavity and the auxiliary cavity are not resonant.The locations of the transparency window and Fano line type depend strongly on the eigen frequency of the auxiliary cavity and the coupling strength between the auxiliary cavity and the waveguide.When one atom is embedded in the first cavity,we show that the transparency window exists even though the first cavity,the atom and the auxiliary cavity are resonant.The Fano line type is strongly dependent on the eigen frequency of the auxiliary cavity and the coupling strength.Our results have potential applications in design of quantum devices at the level of single photon,such as single photon switch and single photon routers.展开更多
Single-photon scattering in a pair of coupled-resonator arrays of waveguides linked by a nanocavity embedded with a two-level system is investigated theoretically.By using the discrete coordinates approach,we deduce t...Single-photon scattering in a pair of coupled-resonator arrays of waveguides linked by a nanocavity embedded with a two-level system is investigated theoretically.By using the discrete coordinates approach,we deduce the analytical expressions for the transmission and reflection amplitudes.The calculations reveal that the transport properties of the single photon can be controlled by adjusting the coupled strength between the nanocavity and the coupled-resonator array.Quantum switching and a 1/4 beam splitter for the band-edge photon based on this structure are also discussed.展开更多
The photon transport in a coupled-resonator waveguide coupled to a two-mode nanocavity embedded with a three-level emitter is investigated.The transmission and reflection amplitudes are obtained by using the discrete ...The photon transport in a coupled-resonator waveguide coupled to a two-mode nanocavity embedded with a three-level emitter is investigated.The transmission and reflection amplitudes are obtained by using the discrete coordinates approach.We show that the coherent transport properties of a single photon can be well controlled by detuning the coupling strength between the two-mode nanocavity and the emitter,and the coupling strength between the nanocavity and the coupled-resonator waveguide. These results may be useful for the design of photonic devices such as optical filters.展开更多
The photon correlation of photon emission from a single quantum dot with cw excitation and pulsed excitation is investigated in details. To calculate the second-order correlation function for optical pumping, we deduc...The photon correlation of photon emission from a single quantum dot with cw excitation and pulsed excitation is investigated in details. To calculate the second-order correlation function for optical pumping, we deduce rate equations with a simplified two-level model under cw excitation and present the master equation approach in the interaction picture to the study of evolution of a three-level system under pulsed excitation. In addition, we report photon correlation measurements on a single self-assembled In0.5Ga0.5As quantum dot, which show strong antibunching behaviour under both the conditions of cw and pulsed excitations. The calculated results are in agreement with the experimental measurements.展开更多
The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the re...The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.展开更多
为了改善串串型无线电能传输(Wireless Power Transfer,WPT)系统在耦合系数变动时无法工作在最优效率的情况,在副边DC-DC变换器上运用占空比寻优法.以Buck-boost变换器为控制对象,通过对比初始占空比变化前后时刻的效率大小,在初始占空...为了改善串串型无线电能传输(Wireless Power Transfer,WPT)系统在耦合系数变动时无法工作在最优效率的情况,在副边DC-DC变换器上运用占空比寻优法.以Buck-boost变换器为控制对象,通过对比初始占空比变化前后时刻的效率大小,在初始占空比的基础上寻找到耦合系数变动后变换器的最优占空比.通过仿真将占空比寻优法与传统的占空比调制法相比较.结果表明:占空比寻优法在耦合系数变动时不仅实现了效率提升,而且还实现了Buck-boost变换器占空比的精确控制.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11105001the Anhui Provincial Natural Science Foundation under Grant Nos 1408085QA22 and 1608085MA09
文摘The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11004001 and 11105001, the Key Project of the Ministry of Education of China under Grant No 212076, and the Anhui Provincial Natural Science Foundation under Grant No 1208085QA09.
文摘Photon scattering properties in one-dimensional waveguide side coupled to a nanocavity embedded in two atoms with dipole-dipole interaction （DDI） are investigated theoretically. The analytical expressions of the transmission and reflection amplitudes are deduced by using the real-space Hamiltonian. A method to determine the coupling strength of DDI is proposed. Realization of single photon switching by modulation the DDI is investigated. The influence of dissipations on the performance of the single photon switching are exhibited. An asymmetric Fano-type resonance, which can be controlled by the DDI, appears in the transmission spectrum.
基金Supported by the Anhui Provincial Natural Science Foundation under Grant Nos 1608085MA05 and 1608085MA09the National Natural Science Foundation of China under Grant Nos 11774262 and 11474003
文摘We theoretically investigate single-photon polarization conversion via scattering by an atom with Λ configuration coupled to a semi-infinite waveguide and discuss the two cases in which the Λ system is non-degenerated and degenerated. By applying the hard-wall boundary condition of the semi-infinite waveguide, it is found that singlephoton polarization conversion can be realized with unit probability for both cases under the ideal condition.Together with the polarization conversion, the frequency conversion of a single photon can also be realized with unit probability in the ideal case if the Λ system is not degenerated.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11864018 and 11574229)the Scientific Research Foundation of Education Department of Jiangxi Province,China(Grant No.GJJ170645)the Doctor Startup Fund of the Natural Science of Jinggangshan University,China(Grant No.JZB16003)
文摘Atom–nanowire coupling system is a promising platform for optical quantum information processing. Unlike the previous designing of optical switch and transistor requiring a dedicated multi-level emitter and high fineness microcavity,a new proposal is put forward which contains a single two-level atom asymmetrically coupled with two nanowires. Singleemitter manipulation of photonic signals for bilateral coherent incident is clear now, since we specify atomic saturation nonlinearity into three contributions which brings us a new approach to realizing light-controlled-light at weak light and single-atom levels. An efficient optically controllable switch based on self-matching-induced-block and a concise optical transistor are proposed. Our findings show potential applications in full-optical devices.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10534030 and 10874134, the National Basic Research Program of China under Grant No 2006CB921504, and the Key Project of Ministry of Education （708063）.
文摘We investigate theoretically the population dynamics and the second-order correlation functions of photon emissions from the biexciton-exciton system of a single quantum dot with excitation from pulses to continuous wave. The dynamic equations of the correlation functions are deduced by applying quantum regression theorem to optical Bloch equations. The influences of excitation pulse width on the correlation function have been discussed in detail.
基金Supported by the Natural Science Foundation of China under Grant Nos 10534030 and 10874134, the National Basic Research Program of China under Grant No 2006CB921504, and Key Project of Ministry of Education of China under Grant No 708063.
文摘We theoretically design a single-mode plasmonic ring nanocavity. Based on the plasmonic cavity, the exciton dynamics between two identical quantum dots （QD-p, QD-q） coupled to the nanocavity are investigated. It is shown that the coupling factors gi （i = p, q） between QD-i and surface plasmons are both equal to 12.53meV in our model and exeiton population swap between the two QDs can be realized. The periods and amplitudes of population oscillations can be modified by the coupling factors. Our results may have potential applications in quantum information and quantum computation on a chip.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11864018 and 11574229)Scientific Research Foundation of the Education Department of Jiangxi Province of China(Grant No.GJJ170645)Doctor Startup Fund of the Natural Science of Jinggangshan University,China(Grant No.JZB16003)
文摘Coherent perfect absorption provides a method of light-controlling-light and has practical applications in optical communications. Recently, a cavity-based nonlinear perfect photon absorption extends the coherent perfect absorber（CPA）beyond the linear regime. As nanowire-based system is a more competitive candidate for full-optical device, we introduce a nonlinear CPA in the single two-level atom–nanowires coupling system in this work. Nonlinear input–output relations are derived analytically, and three contributions of atomic saturation nonlinearity are explicit. The consociation of optical nonlinearity and destructive interference makes it feasible to fabricate a nonlinear monoatomic CPA. Our results also indicate that a nonlinear system may work linearly even when the incoming lights are not weak any more. Our findings show promising applications in full-optical devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.11774262 and 11975023)。
文摘We investigate theoretically single photon transport in one-dimensional waveguide coupled to a pair of cavities,which are denoted by the first cavity and the auxiliary cavity.Two cases with no atom and one atom embedded in the first cavity are discussed.The Fano dips in the transmission spectrum and locations of transparency window are calculated.When no atom is embedded in the first cavity,there exists a transparency window under the condition that the first cavity and the auxiliary cavity are not resonant.The locations of the transparency window and Fano line type depend strongly on the eigen frequency of the auxiliary cavity and the coupling strength between the auxiliary cavity and the waveguide.When one atom is embedded in the first cavity,we show that the transparency window exists even though the first cavity,the atom and the auxiliary cavity are resonant.The Fano line type is strongly dependent on the eigen frequency of the auxiliary cavity and the coupling strength.Our results have potential applications in design of quantum devices at the level of single photon,such as single photon switch and single photon routers.
基金the National Natural Science Foundation of China under Grant Nos 11004001 and 11105001the Key Project of the Ministry of Education of China under Grant No 212076the Anhui Provincial Natural Science Foundation under Grant No 1208085QA09.
文摘Single-photon scattering in a pair of coupled-resonator arrays of waveguides linked by a nanocavity embedded with a two-level system is investigated theoretically.By using the discrete coordinates approach,we deduce the analytical expressions for the transmission and reflection amplitudes.The calculations reveal that the transport properties of the single photon can be controlled by adjusting the coupled strength between the nanocavity and the coupled-resonator array.Quantum switching and a 1/4 beam splitter for the band-edge photon based on this structure are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11004001,11105001 and 11104057the Key Project of Chinese Ministry of Education(No 212076)the Anhui Provincial Natural Science Foundation under Grant No 1208085QA09.
文摘The photon transport in a coupled-resonator waveguide coupled to a two-mode nanocavity embedded with a three-level emitter is investigated.The transmission and reflection amplitudes are obtained by using the discrete coordinates approach.We show that the coherent transport properties of a single photon can be well controlled by detuning the coupling strength between the two-mode nanocavity and the emitter,and the coupling strength between the nanocavity and the coupled-resonator waveguide. These results may be useful for the design of photonic devices such as optical filters.
基金Supported by the National Natural Science Foundation of China under Grant No 10474075.
文摘The photon correlation of photon emission from a single quantum dot with cw excitation and pulsed excitation is investigated in details. To calculate the second-order correlation function for optical pumping, we deduce rate equations with a simplified two-level model under cw excitation and present the master equation approach in the interaction picture to the study of evolution of a three-level system under pulsed excitation. In addition, we report photon correlation measurements on a single self-assembled In0.5Ga0.5As quantum dot, which show strong antibunching behaviour under both the conditions of cw and pulsed excitations. The calculated results are in agreement with the experimental measurements.
基金Supported by the Anhui Provincial Natural Science Foundation under Grant No 1608085MA09the National Natural Science Foundation of China under Grant Nos 11774262,61675006,11474003 and 61472282
文摘The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.
文摘为了改善串串型无线电能传输(Wireless Power Transfer,WPT)系统在耦合系数变动时无法工作在最优效率的情况,在副边DC-DC变换器上运用占空比寻优法.以Buck-boost变换器为控制对象,通过对比初始占空比变化前后时刻的效率大小,在初始占空比的基础上寻找到耦合系数变动后变换器的最优占空比.通过仿真将占空比寻优法与传统的占空比调制法相比较.结果表明:占空比寻优法在耦合系数变动时不仅实现了效率提升,而且还实现了Buck-boost变换器占空比的精确控制.
