Among various quantum machine learning (QML) algorithms, the quantum kernel method has especially attracted attention due to its compatibility with noisy intermediate-scale quantum devices and its potential to achieve quantum advantage. This method performs classification and regression by nonlinearly mapping data into quantum states in a higher-dimensional Hilbert space. Thus far, the quantum kernel method has been implemented only on qubit-based systems, but continuous-variable (CV) systems can potentially offer superior computational power by utilizing its infinite-dimensional Hilbert space. Here, we demonstrate the implementation of the classification task with the CV quantum kernel method on a programmable photonic quantum processor. We experimentally prove that the CV quantum kernel method successfully classifies several datasets robustly even under the experimental imperfections, with high accuracies comparable to the classical kernel. This demonstration sheds light on the utility of CV quantum systems for QML and should stimulate further study in other CV QML algorithms.
{"title":"Continuous-variable quantum kernel method on a programmable photonic quantum processor","authors":"Keitaro Anai, Shion Ikehara, Yoshichika Yano, Daichi Okuno, Shuntaro Takeda","doi":"10.1103/physreva.110.022404","DOIUrl":"https://doi.org/10.1103/physreva.110.022404","url":null,"abstract":"Among various quantum machine learning (QML) algorithms, the quantum kernel method has especially attracted attention due to its compatibility with noisy intermediate-scale quantum devices and its potential to achieve quantum advantage. This method performs classification and regression by nonlinearly mapping data into quantum states in a higher-dimensional Hilbert space. Thus far, the quantum kernel method has been implemented only on qubit-based systems, but continuous-variable (CV) systems can potentially offer superior computational power by utilizing its infinite-dimensional Hilbert space. Here, we demonstrate the implementation of the classification task with the CV quantum kernel method on a programmable photonic quantum processor. We experimentally prove that the CV quantum kernel method successfully classifies several datasets robustly even under the experimental imperfections, with high accuracies comparable to the classical kernel. This demonstration sheds light on the utility of CV quantum systems for QML and should stimulate further study in other CV QML algorithms.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1103/physreva.110.023301
Pieter H. Harkema, Michael Iversen, Anne E. B. Nielsen
The eigenstate thermalization hypothesis describes how isolated many-body quantum systems reach thermal equilibrium. However, quantum many-body scars and Hilbert space fragmentation violate this hypothesis and cause nonthermal behavior. We demonstrate that Hilbert space fragmentation may arise from lattice geometry in a spin- model that conserves the number of domain walls. We generalize a known, one-dimensional, scarred model to larger dimensions and show that this model displays Hilbert space fragmentation on the Vicsek fractal lattice and the two-dimensional lattice. Using Monte Carlo methods, the model is characterized as strongly fragmented on the Vicsek fractal lattice when the number of domain walls is either small or close to the maximal value. On the two-dimensional lattice, the model is strongly fragmented when the density of domain walls is low and weakly fragmented when the density of domain walls is high. Furthermore, we show that the fragmentation persists at a finite density of domain walls in the thermodynamic limit for the Vicsek fractal lattice and the two-dimensional lattice. We also show that the model displays signatures similar to Hilbert space fragmentation on a section of the second-generation hexaflake fractal lattice and a modified two-dimensional lattice. We study the autocorrelation function of local observables and demonstrate that the model displays nonthermal dynamics.
{"title":"Hilbert space fragmentation from lattice geometry","authors":"Pieter H. Harkema, Michael Iversen, Anne E. B. Nielsen","doi":"10.1103/physreva.110.023301","DOIUrl":"https://doi.org/10.1103/physreva.110.023301","url":null,"abstract":"The eigenstate thermalization hypothesis describes how isolated many-body quantum systems reach thermal equilibrium. However, quantum many-body scars and Hilbert space fragmentation violate this hypothesis and cause nonthermal behavior. We demonstrate that Hilbert space fragmentation may arise from lattice geometry in a spin-<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mfrac><mn>1</mn><mn>2</mn></mfrac></math> model that conserves the number of domain walls. We generalize a known, one-dimensional, scarred model to larger dimensions and show that this model displays Hilbert space fragmentation on the Vicsek fractal lattice and the two-dimensional lattice. Using Monte Carlo methods, the model is characterized as strongly fragmented on the Vicsek fractal lattice when the number of domain walls is either small or close to the maximal value. On the two-dimensional lattice, the model is strongly fragmented when the density of domain walls is low and weakly fragmented when the density of domain walls is high. Furthermore, we show that the fragmentation persists at a finite density of domain walls in the thermodynamic limit for the Vicsek fractal lattice and the two-dimensional lattice. We also show that the model displays signatures similar to Hilbert space fragmentation on a section of the second-generation hexaflake fractal lattice and a modified two-dimensional lattice. We study the autocorrelation function of local observables and demonstrate that the model displays nonthermal dynamics.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We measure angle- and phase-resolved photoelectron momentum distributions of multiphoton ionization of xenon atoms using bicircular laser fields. In our experiment, the continuum electron ring currents with larger orbital angular momentum are prepared by an intense circular polarized laser field at 400 nm and probed with a spatiotemporally overlapped corotating or counter-rotating weak 800 nm laser pulse. Interestingly, a distinct “carpetlike” interference pattern in the direction of laser propagation is observed for the counter-rotating fields, but not for the corotating fields. By analyzing the momentum-resolved photoelectron yield oscillations with respect to the two-color relative phase (phase-of-the-phase spectrum), we observe a distinct angular dependence in the phase-of-the-phase spectrum in the laser propagation plane when the fields are counter-rotating. In contrast, in the corotating geometry, the phase-of-the-phase spectrum in the laser propagation plane displays an isotropic phase profile. We explain that the carpetlike interference in the propagation plane arises from the constructive and destructive interference of the continuum electron ring currents with different magnetic quantum number, which can be controlled by the light helicity.
{"title":"Controlling photoelectron interference along the quantization axis of multiphoton ionization in circularly polarized fields","authors":"Yankun Dou, Xiaoxiao Long, Peizeng Li, Peipei Ge, Yongkai Deng, Qihuang Gong, Yunquan Liu","doi":"10.1103/physreva.110.023101","DOIUrl":"https://doi.org/10.1103/physreva.110.023101","url":null,"abstract":"We measure angle- and phase-resolved photoelectron momentum distributions of multiphoton ionization of xenon atoms using bicircular laser fields. In our experiment, the continuum electron ring currents with larger orbital angular momentum are prepared by an intense circular polarized laser field at 400 nm and probed with a spatiotemporally overlapped corotating or counter-rotating weak 800 nm laser pulse. Interestingly, a distinct “carpetlike” interference pattern in the direction of laser propagation is observed for the counter-rotating fields, but not for the corotating fields. By analyzing the momentum-resolved photoelectron yield oscillations with respect to the two-color relative phase (phase-of-the-phase spectrum), we observe a distinct angular dependence in the phase-of-the-phase spectrum in the laser propagation plane when the fields are counter-rotating. In contrast, in the corotating geometry, the phase-of-the-phase spectrum in the laser propagation plane displays an isotropic phase profile. We explain that the carpetlike interference in the propagation plane arises from the constructive and destructive interference of the continuum electron ring currents with different magnetic quantum number, which can be controlled by the light helicity.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, we realize a special class of photonic band gaps (PBGs) called angle-driven PBGs in hybrid one-dimensional (1D) photonic crystals (PhCs) composed of alternating anisotropic metamaterial and dielectric layers. At normal incidence, the effective refractive index of the anisotropic metamaterial is designed to be the same as that of the dielectric. Owing to the lack of refractive index contrast, the angle-driven PBG is closed at normal incidence. Under transverse magnetic (TM) polarization, the effective refractive index of the anisotropic metamaterial is angle-dependent since the isofrequency curve (IFC) is an ellipse or a hyperbola. Therefore, the angle-driven PBG under TM polarization is opened at oblique incidence. However, under transverse electric (TE) polarization, the effective refractive index of the anisotropic metamaterial is angle-independent since the IFC is a circle. Therefore, the angle-driven PBG under TE polarization remains closed. In hybrid 1D PhCs composed of alternating elliptical metamaterial and dielectric layers, we realize blueshift angle-driven PBGs under TM polarization. As the incident angle increases, the angle-driven PBG shifts towards shorter wavelengths. Empowered by the blueshift angle-driven PBG, broadband polarization selection and privacy protection can be achieved. In hybrid 1D PhCs composed of alternating hyperbolic metamaterial and dielectric layers, we realize zero-shift angle-driven PBGs under TM polarization. As the incident angle increases, the angle-driven PBG stays almost unchanged. Empowered by the zero-shift angle-driven PBG, wide-angle polarization selection can be achieved. In addition, blueshift and zero-shift angle-driven Tamm plasmon polaritons (TPPs) are realized by placing a metal layer in front of the hybrid 1D PhCs. Our work not only offers an elegant platform to realize angle-driven PBGs and angle-driven TPPs, but also facilitates the development of high-performance polarizers.
{"title":"Hybrid one-dimensional photonic crystals containing anisotropic metamaterials: Angle-driven photonic band gaps and angle-driven Tamm plasmon polaritons","authors":"Feng Wu, Yuchun She, Tingting Zhou, Zhaoming Cheng, Jianhao Huang","doi":"10.1103/physreva.110.023503","DOIUrl":"https://doi.org/10.1103/physreva.110.023503","url":null,"abstract":"Herein, we realize a special class of photonic band gaps (PBGs) called angle-driven PBGs in hybrid one-dimensional (1D) photonic crystals (PhCs) composed of alternating anisotropic metamaterial and dielectric layers. At normal incidence, the effective refractive index of the anisotropic metamaterial is designed to be the same as that of the dielectric. Owing to the lack of refractive index contrast, the angle-driven PBG is closed at normal incidence. Under transverse magnetic (TM) polarization, the effective refractive index of the anisotropic metamaterial is angle-dependent since the isofrequency curve (IFC) is an ellipse or a hyperbola. Therefore, the angle-driven PBG under TM polarization is opened at oblique incidence. However, under transverse electric (TE) polarization, the effective refractive index of the anisotropic metamaterial is angle-independent since the IFC is a circle. Therefore, the angle-driven PBG under TE polarization remains closed. In hybrid 1D PhCs composed of alternating elliptical metamaterial and dielectric layers, we realize blueshift angle-driven PBGs under TM polarization. As the incident angle increases, the angle-driven PBG shifts towards shorter wavelengths. Empowered by the blueshift angle-driven PBG, broadband polarization selection and privacy protection can be achieved. In hybrid 1D PhCs composed of alternating hyperbolic metamaterial and dielectric layers, we realize zero-shift angle-driven PBGs under TM polarization. As the incident angle increases, the angle-driven PBG stays almost unchanged. Empowered by the zero-shift angle-driven PBG, wide-angle polarization selection can be achieved. In addition, blueshift and zero-shift angle-driven Tamm plasmon polaritons (TPPs) are realized by placing a metal layer in front of the hybrid 1D PhCs. Our work not only offers an elegant platform to realize angle-driven PBGs and angle-driven TPPs, but also facilitates the development of high-performance polarizers.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1103/physreva.110.022205
S. Malikis, V. Cheianov
The quantum brachistochrone problem addresses the fundamental challenge of achieving the quantum speed limit in applications aiming to realize a given unitary operation in a quantum system. Specifically, it looks into optimization of the transformation of quantum states through controlled Hamiltonians, which form a small subset in the space of the system's observables. Here we introduce a broad family of completely integrable brachistochrone protocols, which arise from a judicious choice of the control Hamiltonian subset. Furthermore, we demonstrate how the inherent stability of the completely integrable protocols makes them numerically tractable and therefore practicable as opposed to their nonintegrable counterparts.
{"title":"Integrability and chaos in the quantum brachistochrone problem","authors":"S. Malikis, V. Cheianov","doi":"10.1103/physreva.110.022205","DOIUrl":"https://doi.org/10.1103/physreva.110.022205","url":null,"abstract":"The quantum brachistochrone problem addresses the fundamental challenge of achieving the quantum speed limit in applications aiming to realize a given unitary operation in a quantum system. Specifically, it looks into optimization of the transformation of quantum states through controlled Hamiltonians, which form a small subset in the space of the system's observables. Here we introduce a broad family of completely integrable brachistochrone protocols, which arise from a judicious choice of the control Hamiltonian subset. Furthermore, we demonstrate how the inherent stability of the completely integrable protocols makes them numerically tractable and therefore practicable as opposed to their nonintegrable counterparts.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1103/physreva.110.l020801
S. S. Baturin, A. V. Volotka
We develop a simple model and propose a scheme that allows the production of twisted atoms in free space using the absorption of twisted photons by a bound electron. We show that in the inelastic collision of a photon and an atom, the twisted state of the photon is transferred to the center-of-mass state, so that the projection of the orbital momentum of the atom becomes . We also show that, depending on the experimental conditions, the twistedness of the photon is either transferred to the atomic center-of-mass quantum state or modifies the selection rule for the bound electron transition. The proposed scheme is general and enables complex shaping of the atomic wavefront.
{"title":"Conversion of twistedness from light to atoms","authors":"S. S. Baturin, A. V. Volotka","doi":"10.1103/physreva.110.l020801","DOIUrl":"https://doi.org/10.1103/physreva.110.l020801","url":null,"abstract":"We develop a simple model and propose a scheme that allows the production of twisted atoms in free space using the absorption of twisted photons by a bound electron. We show that in the inelastic collision of a photon and an atom, the twisted state of the photon is transferred to the center-of-mass state, so that the projection of the orbital momentum of the atom becomes <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>m</mi><mi>γ</mi></msub><mo>−</mo><mi mathvariant=\"normal\">Δ</mi><msub><mi>m</mi><mi>e</mi></msub></mrow></math>. We also show that, depending on the experimental conditions, the twistedness of the photon is either transferred to the atomic center-of-mass quantum state or modifies the selection rule for the bound electron transition. The proposed scheme is general and enables complex shaping of the atomic wavefront.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1103/physreva.110.023701
Eric Lantz, Fabrice Devaux, Serge Massar
Subtracting accidental coincidences is a common practice in quantum optics experiments. For zero mean Gaussian states, such as a squeezed vacuum, we show that if one removes accidental coincidences, the measurement results are quantitatively the same for both photon coincidences at very low flux and intensity covariances. Consequently, pure quantum effects at the photon level, like interference of photon wave functions or photon bunching, are reproduced in the correlation of fluctuations of macroscopic beams issued from spontaneous down-conversion. This is true both in experiment if the detection resolution is smaller than the coherence cell (size of the mode) and in stochastic simulations based on sampling the Wigner function. We also discuss the limitations of this correspondence, such as Bell inequalities (for which one cannot subtract accidental coincidences), highly multimode situations such as quantum imaging, and higher-order correlations.
{"title":"Detecting single photons is not always necessary to evidence interference of photon probability amplitudes","authors":"Eric Lantz, Fabrice Devaux, Serge Massar","doi":"10.1103/physreva.110.023701","DOIUrl":"https://doi.org/10.1103/physreva.110.023701","url":null,"abstract":"Subtracting accidental coincidences is a common practice in quantum optics experiments. For zero mean Gaussian states, such as a squeezed vacuum, we show that if one removes accidental coincidences, the measurement results are quantitatively the same for both photon coincidences at very low flux and intensity covariances. Consequently, pure quantum effects at the photon level, like interference of photon wave functions or photon bunching, are reproduced in the correlation of fluctuations of macroscopic beams issued from spontaneous down-conversion. This is true both in experiment if the detection resolution is smaller than the coherence cell (size of the mode) and in stochastic simulations based on sampling the Wigner function. We also discuss the limitations of this correspondence, such as Bell inequalities (for which one cannot subtract accidental coincidences), highly multimode situations such as quantum imaging, and higher-order correlations.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1103/physreva.110.022402
Yijia Xu (许逸葭), Yixu Wang (王亦许), Victor V. Albert
We develop quantum information processing primitives for the planar rotor, the state space of a particle on a circle. The -rotor Clifford group, , is represented by continuous gates generated by polynomials quadratic in angular momenta, as well as discrete gates generated by momentum sign-flip and sum gates. Our understanding of this group allows us to establish connections between homological rotor error-correcting codes [Vuillot, Ciani, and Terhal, Commun. Math. Phys.405, 53 (2024)] and oscillator quantum codes, including Gottesman-Kitaev-Preskill codes and rotation-symmetric bosonic codes. Inspired by homological rotor codes, we provide a systematic construction of multimode rotation-symmetric bosonic codes by making a parallel between oscillator Fock states and rotor states with fixed non-negative angular momentum. This family of homological number-phase codes protects against dephasing and changes in occupation number. Encoding and decoding circuits for these codes can be derived from the corresponding rotor Clifford operations. As a result of independent interest, we show how to nondestructively measure the oscillator phase using conditional occupation-number addition and postselection. We also outline several rotor and oscillator varieties of the Gottesman-Kitaev-Preskill-stabilizer codes [Phys. Rev. Lett.125, 080503 (2020).].
{"title":"Multimode rotation-symmetric bosonic codes from homological rotor codes","authors":"Yijia Xu (许逸葭), Yixu Wang (王亦许), Victor V. Albert","doi":"10.1103/physreva.110.022402","DOIUrl":"https://doi.org/10.1103/physreva.110.022402","url":null,"abstract":"We develop quantum information processing primitives for the planar rotor, the state space of a particle on a circle. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math>-rotor Clifford group, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mtext>U</mtext><msup><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>n</mi><mo>(</mo><mi>n</mi><mo>+</mo><mn>1</mn><mo>)</mo><mo>/</mo><mn>2</mn></mrow></msup><mo>⋊</mo><msub><mtext>GL</mtext><mi>n</mi></msub><mrow><mo>(</mo><mi mathvariant=\"double-struck\">Z</mi><mo>)</mo></mrow></mrow></math>, is represented by continuous <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mtext>U</mtext><mo>(</mo><mn>1</mn><mo>)</mo></mrow></math> gates generated by polynomials quadratic in angular momenta, as well as discrete <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mtext>GL</mtext><mi>n</mi></msub><mrow><mo>(</mo><mi mathvariant=\"double-struck\">Z</mi><mo>)</mo></mrow></mrow></math> gates generated by momentum sign-flip and sum gates. Our understanding of this group allows us to establish connections between homological rotor error-correcting codes [Vuillot, Ciani, and Terhal, <span>Commun. Math. Phys.</span> <b>405</b>, 53 (2024)] and oscillator quantum codes, including Gottesman-Kitaev-Preskill codes and rotation-symmetric bosonic codes. Inspired by homological rotor codes, we provide a systematic construction of multimode rotation-symmetric bosonic codes by making a parallel between oscillator Fock states and rotor states with fixed non-negative angular momentum. This family of homological number-phase codes protects against dephasing and changes in occupation number. Encoding and decoding circuits for these codes can be derived from the corresponding rotor Clifford operations. As a result of independent interest, we show how to nondestructively measure the oscillator phase using conditional occupation-number addition and postselection. We also outline several rotor and oscillator varieties of the Gottesman-Kitaev-Preskill-stabilizer codes [<span>Phys. Rev. Lett.</span> <b>125</b>, 080503 (2020).].","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1103/physreva.110.023502
Zhi-Xiang Su, Ai-Dong Zhu, Lin Yu
We propose a scheme for achieving twofold nonreciprocal optomechanically induced transparency (OMIT) in a three-cavity optomechanical system. In this system, an optical microring resonator is evanescently coupled to two microring optomechanical resonators simultaneously, and a beam splitter is utilized to establish two distinct optical paths. By utilizing a strong control laser and a weak probe laser to drive the resonators, a twofold nonreciprocal OMIT phenomenon can be observed. Specifically, the distinct propagation direction of the control laser will result in nonreciprocal OMIT in the two different paths, respectively. In contrast to two-cavity optomechanical systems, the OMIT can be significantly enhanced through indirect coupling, resulting in an increase at the frequency resonance. This unique structure of a three-cavity system renders it an ideal optical single-pole double-throw (SPDT) switch or an ideal optical SPDT-like isolator, which can play an pivotal role in optical communication networks and present exciting opportunities in quantum technologies.
{"title":"Single-pole double-throw–type optomechanically induced transparency","authors":"Zhi-Xiang Su, Ai-Dong Zhu, Lin Yu","doi":"10.1103/physreva.110.023502","DOIUrl":"https://doi.org/10.1103/physreva.110.023502","url":null,"abstract":"We propose a scheme for achieving twofold nonreciprocal optomechanically induced transparency (OMIT) in a three-cavity optomechanical system. In this system, an optical microring resonator is evanescently coupled to two microring optomechanical resonators simultaneously, and a beam splitter is utilized to establish two distinct optical paths. By utilizing a strong control laser and a weak probe laser to drive the resonators, a twofold nonreciprocal OMIT phenomenon can be observed. Specifically, the distinct propagation direction of the control laser will result in nonreciprocal OMIT in the two different paths, respectively. In contrast to two-cavity optomechanical systems, the OMIT can be significantly enhanced through indirect coupling, resulting in an <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>∼</mo><mn>23.4</mn><mo>%</mo></mrow></math> increase at the frequency resonance. This unique structure of a three-cavity system renders it an ideal optical single-pole double-throw (SPDT) switch or an ideal optical SPDT-like isolator, which can play an pivotal role in optical communication networks and present exciting opportunities in quantum technologies.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1103/physreva.110.023704
Eduardo C. Lima, Breno Marques, Marcelo Martinelli, Luciano S. Cruz
Quantum state production and characterization are fundamental elements for many quantum technological applications. In this paper, we studied the generation of polarization quantum states by interacting light with a Kerr medium and the dependency of the outcome on orthogonal polarization seeding. Starting from coherent states produced by Ti:sapphire laser, interaction with a warm vapor cell led to noise compression of after correction of the detection quantum efficiency). Experimental characterization of the effect of an orthogonal polarization light seed on squeezing is shown to agree with the theoretical model.
{"title":"Role of seeding in the generation of polarization squeezed light by an atomic Kerr medium","authors":"Eduardo C. Lima, Breno Marques, Marcelo Martinelli, Luciano S. Cruz","doi":"10.1103/physreva.110.023704","DOIUrl":"https://doi.org/10.1103/physreva.110.023704","url":null,"abstract":"Quantum state production and characterization are fundamental elements for many quantum technological applications. In this paper, we studied the generation of polarization quantum states by interacting light with a Kerr medium and the dependency of the outcome on orthogonal polarization seeding. Starting from coherent states produced by Ti:sapphire laser, interaction with a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Rb</mi><mprescripts></mprescripts><none></none><mn>87</mn></mmultiscripts></math> warm vapor cell led to noise compression of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>−</mo><mn>5.2</mn><mo>±</mo><mn>0.5</mn><mspace width=\"0.28em\"></mspace><mi>dB</mi><mspace width=\"4pt\"></mspace><mo>(</mo><mn>6.4</mn><mo>±</mo><mn>0.6</mn><mspace width=\"0.28em\"></mspace><mi>dB</mi></mrow></math> after correction of the detection quantum efficiency). Experimental characterization of the effect of an orthogonal polarization light seed on squeezing is shown to agree with the theoretical model.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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