Pub Date : 2024-09-18DOI: 10.1088/1367-2630/ad78f9
Yizhi You
A wide variety of higher-order symmetry-protected topological phases (HOSPT) with gapless corners or hinges have been proposed as descendants of topological crystalline insulators protected by spatial symmetry. In this work, we address a new class of higher-order topological states that do not require crystalline symmetries but instead rely on subsystem symmetry for protection. We propose several strongly interacting models with gapless hinges or corners based on a decorated hinge-wall condensate picture. The hinge-wall, which appears as the defect configuration of a Z2 paramagnet, is decorated with a lower-dimensional SPT state. Such a unique hinge-wall decoration structure leads to gapped surfaces separated by gapless hinges. The non-trivial nature of the hinge modes can be captured by a D conformal field theory with a Wess–Zumino–Witten term. Moreover, we establish a no-go theorem to demonstrate the ungappable nature of the hinges by making a connection between the generalized Lieb–Schultz–Mattis theorem and the boundary anomaly of the HOSPT state. This universal correspondence engenders a comprehensive criterion to determine the existence of HOSPT under certain symmetries, regardless of the microscopic Hamiltonian.
{"title":"Higher-order topological phase with subsystem symmetries","authors":"Yizhi You","doi":"10.1088/1367-2630/ad78f9","DOIUrl":"https://doi.org/10.1088/1367-2630/ad78f9","url":null,"abstract":"A wide variety of higher-order symmetry-protected topological phases (HOSPT) with gapless corners or hinges have been proposed as descendants of topological crystalline insulators protected by spatial symmetry. In this work, we address a new class of higher-order topological states that do not require crystalline symmetries but instead rely on subsystem symmetry for protection. We propose several strongly interacting models with gapless hinges or corners based on a decorated hinge-wall condensate picture. The hinge-wall, which appears as the defect configuration of a Z2 paramagnet, is decorated with a lower-dimensional SPT state. Such a unique hinge-wall decoration structure leads to gapped surfaces separated by gapless hinges. The non-trivial nature of the hinge modes can be captured by a D conformal field theory with a Wess–Zumino–Witten term. Moreover, we establish a no-go theorem to demonstrate the ungappable nature of the hinges by making a connection between the generalized Lieb–Schultz–Mattis theorem and the boundary anomaly of the HOSPT state. This universal correspondence engenders a comprehensive criterion to determine the existence of HOSPT under certain symmetries, regardless of the microscopic Hamiltonian.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257806","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 : 2024-09-17DOI: 10.1088/1367-2630/ad787d
Torgom Yezekyan, Sergejs Boroviks, Olivier J F Martin and Sergey I Bozhevolnyi
The occurrence of quasi-bound states in the continuum (qBIC) in all-dielectric asymmetric grating waveguide couplers with different degrees of asymmetry under normal light incidence is analysed from the viewpoint of identifying the most promising configuration for realizing the highest quality (Q) factor under the condition of utmost efficiency (i.e. total extinction). Considering asymmetric gratings produced by altering every Nth ridge of a conventional (symmetric) grating coupler, we analyse different regimes corresponding to the interplay between diffractive coupling to waveguide modes and band gap effects caused by the Bragg reflection of waveguide modes. The symmetric and double- and triple-period asymmetric grating couplers are considered in detail for the same unperturbed two-mode waveguide and the grating coupler parameters that ensure the occurrence of total transmission extinction at the same wavelengths. It is found that the highest Q is expected for the double-period asymmetric grating, a feature that we explain by the circumstance that the first-order distributed Bragg resonator (DBR) is realized for this configuration while, for other configurations, the second-order DBR comes into play. Experiments conducted at telecom wavelengths for all three cases using thin-film Al2O3-on-MgF2 waveguides and Ge diffraction gratings exhibit the transmission spectra in qualitative agreement with numerical simulations. Since the occurrence of considered qBIC can be analytically predicted, the results obtained may serve as reliable guidelines for intelligent engineering of asymmetric grating waveguide couplers enabling highly resonant, linear and nonlinear, electromagnetic interactions.
我们分析了全介质非对称光栅波导耦合器在正常光入射条件下不同不对称程度的连续体中准束缚态（qBIC）的发生，目的是找出在最高效率（即全消光）条件下实现最高质量（Q）因子的最有前途的配置。考虑到非对称光栅是通过改变传统（对称）光栅耦合器的每N个脊而产生的，我们分析了与波导模式的衍射耦合和波导模式的布拉格反射所引起的带隙效应之间的相互作用相对应的不同状态。我们详细研究了对称光栅耦合器、双周期和三周期非对称光栅耦合器，对于相同的无扰动双模波导和光栅耦合器参数，这些参数可确保在相同波长上发生全透射消光。我们发现，双周期不对称光栅的 Q 值最高，这是因为这种配置采用了一阶分布式布拉格共振器（DBR），而其他配置则采用了二阶分布式布拉格共振器。在电信波长下，使用 Al2O3-on-MgF2 薄膜波导和 Ge 衍射光栅对所有三种情况进行了实验，结果显示传输光谱与数值模拟结果基本一致。由于可以分析预测所考虑的 qBIC 的发生，因此所获得的结果可作为非对称光栅波导耦合器智能工程的可靠指南，从而实现高谐振、线性和非线性电磁相互作用。
{"title":"Engineering quasi-bound states in the continuum in asymmetric waveguide gratings","authors":"Torgom Yezekyan, Sergejs Boroviks, Olivier J F Martin and Sergey I Bozhevolnyi","doi":"10.1088/1367-2630/ad787d","DOIUrl":"https://doi.org/10.1088/1367-2630/ad787d","url":null,"abstract":"The occurrence of quasi-bound states in the continuum (qBIC) in all-dielectric asymmetric grating waveguide couplers with different degrees of asymmetry under normal light incidence is analysed from the viewpoint of identifying the most promising configuration for realizing the highest quality (Q) factor under the condition of utmost efficiency (i.e. total extinction). Considering asymmetric gratings produced by altering every Nth ridge of a conventional (symmetric) grating coupler, we analyse different regimes corresponding to the interplay between diffractive coupling to waveguide modes and band gap effects caused by the Bragg reflection of waveguide modes. The symmetric and double- and triple-period asymmetric grating couplers are considered in detail for the same unperturbed two-mode waveguide and the grating coupler parameters that ensure the occurrence of total transmission extinction at the same wavelengths. It is found that the highest Q is expected for the double-period asymmetric grating, a feature that we explain by the circumstance that the first-order distributed Bragg resonator (DBR) is realized for this configuration while, for other configurations, the second-order DBR comes into play. Experiments conducted at telecom wavelengths for all three cases using thin-film Al2O3-on-MgF2 waveguides and Ge diffraction gratings exhibit the transmission spectra in qualitative agreement with numerical simulations. Since the occurrence of considered qBIC can be analytically predicted, the results obtained may serve as reliable guidelines for intelligent engineering of asymmetric grating waveguide couplers enabling highly resonant, linear and nonlinear, electromagnetic interactions.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257807","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 : 2024-09-15DOI: 10.1088/1367-2630/ad7631
S T Kempers, I J M van Elk, K A H van Leeuwen and O J Luiten
Photon-Induced Near-field Electron Microscopy (PINEM), Kapitza–Dirac (KD) gratings, and ponderomotive phase plates are examples of techniques in which the wave function of an electron in free space is manipulated using light fields: free electron quantum optics (FEQO). These effects are usually treated in separate theoretical frameworks. In this paper we present a unified, two-pronged framework that can be used to describe and numerically evaluate the performance of a number of FEQO-based electron-optical elements. The first part is a combination of existing analytical treatments of light-electron scattering, based on solving a relativistically corrected Schrödinger equation. The theoretical overview covers both second-order contributions to PINEM and the Kapitza–Dirac effect. The second, novel element of the approach is based on electron wavefront reconstruction by evaluating the quantum mechanical phase along a bundle of classical electron trajectories. The quasi-classical (but fully relativistic) approach lends itself to simulating a wide variety of FEQO devices, including the examples mentioned. We apply both approaches to a few specific experimental configurations: mirror-based first-order PINEM, second-order PINEM in very high laser intensity, and Kapitza–Dirac diffraction. The results show excellent agreement between the analytical results and the quasi-classical simulations. Finally, we propose a setup that combines KD and PINEM to allow for simultaneous coherent energy and transverse momentum shaping of an electron beam, and present simulation results thereof.
{"title":"Coherent electron phase-space manipulation by combined elastic and inelastic light-electron scattering","authors":"S T Kempers, I J M van Elk, K A H van Leeuwen and O J Luiten","doi":"10.1088/1367-2630/ad7631","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7631","url":null,"abstract":"Photon-Induced Near-field Electron Microscopy (PINEM), Kapitza–Dirac (KD) gratings, and ponderomotive phase plates are examples of techniques in which the wave function of an electron in free space is manipulated using light fields: free electron quantum optics (FEQO). These effects are usually treated in separate theoretical frameworks. In this paper we present a unified, two-pronged framework that can be used to describe and numerically evaluate the performance of a number of FEQO-based electron-optical elements. The first part is a combination of existing analytical treatments of light-electron scattering, based on solving a relativistically corrected Schrödinger equation. The theoretical overview covers both second-order contributions to PINEM and the Kapitza–Dirac effect. The second, novel element of the approach is based on electron wavefront reconstruction by evaluating the quantum mechanical phase along a bundle of classical electron trajectories. The quasi-classical (but fully relativistic) approach lends itself to simulating a wide variety of FEQO devices, including the examples mentioned. We apply both approaches to a few specific experimental configurations: mirror-based first-order PINEM, second-order PINEM in very high laser intensity, and Kapitza–Dirac diffraction. The results show excellent agreement between the analytical results and the quasi-classical simulations. Finally, we propose a setup that combines KD and PINEM to allow for simultaneous coherent energy and transverse momentum shaping of an electron beam, and present simulation results thereof.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257832","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 : 2024-09-15DOI: 10.1088/1367-2630/ad77ee
Baibhab Bose, Devvrat Tiwari and Subhashish Banerjee
The field of information scrambling has seen significant growth over the last decade, where the out-of-time-ordered correlator (OTOC) has emerged as a prominent tool to probe it. In this work, we use bipartite OTOC, a particular form of OTOC, to study information scrambling in the atom–field interaction models and the model of the Ising spin chain interacting with a tilted magnetic field. This is done considering the effects of open quantum systems. A relationship between information scrambling, using bipartite OTOC, and irreversibility, using entropy production, is probed under unitary dynamics. The equivalence of bipartite OTOC with operator entanglement is explicitly shown for the Ising model.
{"title":"Bipartite OTOC in open quantum systems: information scrambling and irreversibility","authors":"Baibhab Bose, Devvrat Tiwari and Subhashish Banerjee","doi":"10.1088/1367-2630/ad77ee","DOIUrl":"https://doi.org/10.1088/1367-2630/ad77ee","url":null,"abstract":"The field of information scrambling has seen significant growth over the last decade, where the out-of-time-ordered correlator (OTOC) has emerged as a prominent tool to probe it. In this work, we use bipartite OTOC, a particular form of OTOC, to study information scrambling in the atom–field interaction models and the model of the Ising spin chain interacting with a tilted magnetic field. This is done considering the effects of open quantum systems. A relationship between information scrambling, using bipartite OTOC, and irreversibility, using entropy production, is probed under unitary dynamics. The equivalence of bipartite OTOC with operator entanglement is explicitly shown for the Ising model.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257808","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 : 2024-09-12DOI: 10.1088/1367-2630/ad76d3
Yewei Tao, Kaipeng Hu, Pengyue Wang, Xiaoqian Zhao and Lei Shi
Interaction diversity and interaction identity, as two classic interaction patterns in real-world systems, are frequently employed to probe into the cooperative dilemmas among participants with diverse interaction identities within groups. Considering the influence of factors such as hyperlink configurations on the evolution of cooperation within complex networks, this study particularly focuses on the organic integration of hypergraphs and diverse interaction modes. Employing the public goods game model in uniformly stochastic hypergraphs, we explore the effects of synergy factors and diverse interacting individuals on the cooperation rate and strategy consistency within hyperlinks. We emphasize that the diverse interacting individuals are a double-edged sword, and the controlled number of such individuals is conducive to the evolution of cooperation. The findings of this study reveal the significance of these two typical interaction patterns and provide valuable insights for coordinating them to achieve social optimality in cooperation.
{"title":"A double-edged sword: diverse interactions in hypergraphs","authors":"Yewei Tao, Kaipeng Hu, Pengyue Wang, Xiaoqian Zhao and Lei Shi","doi":"10.1088/1367-2630/ad76d3","DOIUrl":"https://doi.org/10.1088/1367-2630/ad76d3","url":null,"abstract":"Interaction diversity and interaction identity, as two classic interaction patterns in real-world systems, are frequently employed to probe into the cooperative dilemmas among participants with diverse interaction identities within groups. Considering the influence of factors such as hyperlink configurations on the evolution of cooperation within complex networks, this study particularly focuses on the organic integration of hypergraphs and diverse interaction modes. Employing the public goods game model in uniformly stochastic hypergraphs, we explore the effects of synergy factors and diverse interacting individuals on the cooperation rate and strategy consistency within hyperlinks. We emphasize that the diverse interacting individuals are a double-edged sword, and the controlled number of such individuals is conducive to the evolution of cooperation. The findings of this study reveal the significance of these two typical interaction patterns and provide valuable insights for coordinating them to achieve social optimality in cooperation.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214663","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 : 2024-09-12DOI: 10.1088/1367-2630/ad6eae
Xiao-Long Lü and Jun-Feng Liu
Pseudohelical edge state (PHES) was proposed based on a staggered spin–orbit coupling (SOC) uniformly applied on graphene. In this work, we investigate the formation of the PHES and its edge-state transitions by the side potentials composed of a uniform SOC, an antiferromagnetic exchange field and a staggered electric field that are applied on the boundaries in zigzag graphene nanoribbon. The results reveal that the PHESs can also be achieved by the side potential of the antisymmetric uniform spin–orbit coupling, which is attributed to the fact that the opposite (same) sign of energies at the valleys and indicates the presence (absence) of the edge state. Based on this modulated mechanism, the PHES can be further transformed into two different types of the PHESs, spin-polarized antichiral edge states (AESs) and one-sided spin-polarized AESs, by modulating the applied direction and location of the side potentials. More strikingly, by utilizing these edge-state transitions, we propose a spin dual-channel or single-channel field-effect transistor that can be operated by a staggered electric field. Moreover, we confirm that the proposed transistor is robust against disorders, with the assistance of calculating the transmission.
{"title":"Generation and edge-state transitions of pseudohelical edge state based on side potentials in graphene","authors":"Xiao-Long Lü and Jun-Feng Liu","doi":"10.1088/1367-2630/ad6eae","DOIUrl":"https://doi.org/10.1088/1367-2630/ad6eae","url":null,"abstract":"Pseudohelical edge state (PHES) was proposed based on a staggered spin–orbit coupling (SOC) uniformly applied on graphene. In this work, we investigate the formation of the PHES and its edge-state transitions by the side potentials composed of a uniform SOC, an antiferromagnetic exchange field and a staggered electric field that are applied on the boundaries in zigzag graphene nanoribbon. The results reveal that the PHESs can also be achieved by the side potential of the antisymmetric uniform spin–orbit coupling, which is attributed to the fact that the opposite (same) sign of energies at the valleys and indicates the presence (absence) of the edge state. Based on this modulated mechanism, the PHES can be further transformed into two different types of the PHESs, spin-polarized antichiral edge states (AESs) and one-sided spin-polarized AESs, by modulating the applied direction and location of the side potentials. More strikingly, by utilizing these edge-state transitions, we propose a spin dual-channel or single-channel field-effect transistor that can be operated by a staggered electric field. Moreover, we confirm that the proposed transistor is robust against disorders, with the assistance of calculating the transmission.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214689","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 : 2024-09-12DOI: 10.1088/1367-2630/ad77ec
Ming-Gen Li, Rui Xing, Li-Ming Fan, Meng Hu, Jing-Dong Bao and Peng-Cheng Li
When dealing with heterogeneous systems, interpreting the mean-square displacement (MSD) data appropriately is crucial. This is due to the limitation that the various interpretations of stochastic differential equations with state-dependent diffusivity may yield the same MSD data, leading to erroneous conclusions. Aided by analytical MSD solutions supported by Langevin simulations, we explore this limitation in diffusion processes exhibiting power-law state-dependent diffusivity, , with diffusion constant D0 and scaling index µ. We find that distinct interpretations leading to same MSD data possess different D0 values. A method is introduced to discern these D0-dependent interpretations. When applying the method to subdiffusion MSD data, we observe interpretation transitions depending on the value of the anomalous diffusion coefficient. Furthermore, we demonstrate that these D0-dependent interpretations respond diversely to memory effects, which may also be used to decide on the interpretation of MSD data. We believe that these findings offer insights for interpreting MSD data in heterogeneous systems.
{"title":"On the interpretation of mean-square displacement in heterogeneous systems","authors":"Ming-Gen Li, Rui Xing, Li-Ming Fan, Meng Hu, Jing-Dong Bao and Peng-Cheng Li","doi":"10.1088/1367-2630/ad77ec","DOIUrl":"https://doi.org/10.1088/1367-2630/ad77ec","url":null,"abstract":"When dealing with heterogeneous systems, interpreting the mean-square displacement (MSD) data appropriately is crucial. This is due to the limitation that the various interpretations of stochastic differential equations with state-dependent diffusivity may yield the same MSD data, leading to erroneous conclusions. Aided by analytical MSD solutions supported by Langevin simulations, we explore this limitation in diffusion processes exhibiting power-law state-dependent diffusivity, , with diffusion constant D0 and scaling index µ. We find that distinct interpretations leading to same MSD data possess different D0 values. A method is introduced to discern these D0-dependent interpretations. When applying the method to subdiffusion MSD data, we observe interpretation transitions depending on the value of the anomalous diffusion coefficient. Furthermore, we demonstrate that these D0-dependent interpretations respond diversely to memory effects, which may also be used to decide on the interpretation of MSD data. We believe that these findings offer insights for interpreting MSD data in heterogeneous systems.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214688","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 : 2024-09-12DOI: 10.1088/1367-2630/ad77ed
Jun-Tao He, Hui-Jun Li, Ji Lin and Boris A Malomed
We analytically and numerically study three-component rogue waves (RWs) in spin-1 Bose–Einstein condensates with Raman-induced spin–orbit coupling (SOC). Using the multiscale perturbative method, we obtain approximate analytical solutions for RWs with positive and negative effective masses, determined by the effective dispersion of the system. The solutions include RWs with smooth and striped shapes, as well as higher-order RWs. The analytical solutions demonstrate that the RWs in the three components of the system exhibit different velocities and their maximum peaks appear at the same spatiotemporal position, which is caused by SOC and interactions. The accuracy of the approximate analytical solutions is corroborated by comparison with direct numerical simulations of the underlying system. Additionally, we systematically explore existence domains for the RWs determined by the baseband modulational instability (BMI). Numerical simulations corroborate that, under the action of BMI, plane waves with random initial perturbations excite RWs, as predicted by the approximate analytical solutions.
{"title":"Vector rogue waves in spin-1 Bose–Einstein condensates with spin–orbit coupling","authors":"Jun-Tao He, Hui-Jun Li, Ji Lin and Boris A Malomed","doi":"10.1088/1367-2630/ad77ed","DOIUrl":"https://doi.org/10.1088/1367-2630/ad77ed","url":null,"abstract":"We analytically and numerically study three-component rogue waves (RWs) in spin-1 Bose–Einstein condensates with Raman-induced spin–orbit coupling (SOC). Using the multiscale perturbative method, we obtain approximate analytical solutions for RWs with positive and negative effective masses, determined by the effective dispersion of the system. The solutions include RWs with smooth and striped shapes, as well as higher-order RWs. The analytical solutions demonstrate that the RWs in the three components of the system exhibit different velocities and their maximum peaks appear at the same spatiotemporal position, which is caused by SOC and interactions. The accuracy of the approximate analytical solutions is corroborated by comparison with direct numerical simulations of the underlying system. Additionally, we systematically explore existence domains for the RWs determined by the baseband modulational instability (BMI). Numerical simulations corroborate that, under the action of BMI, plane waves with random initial perturbations excite RWs, as predicted by the approximate analytical solutions.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214686","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 : 2024-09-12DOI: 10.1088/1367-2630/ad7635
D Dlaka, P Androvitsaneas, A Young, Q Ma, E Harbord and Ruth Oulton
Quantum dots have the potential to be one of the brightest deterministic single photon sources with high end applications in quantum computing and cluster state generation. In this work, we re-examine the design of plain micropillars by meticulously examining the structural effects of the decay into leaky channels beyond an atom-like cavity estimation. We show that precise control of the side losses with the diameter and avoidance of propagating Bloch modes in the distributed Bragg reflectors can result in easy-to-manufacture broadband ( –2500) micropillars, allowing for broad optical coherent control pulses necessary for high single photon purity ( 99.2%–99.99% achievable) while simultaneously demonstrating extremely high efficiency out the top (90.5%–96.4%). We also demonstrate that such cavities naturally decouple from the phonon sideband, with the phonon sideband reducing by a factor of 5–33 allowing us to predict that the photons should show 98.5%–99.8% indistinguishability without the need for filtering.
{"title":"Design principles for > 90 % ...","authors":"D Dlaka, P Androvitsaneas, A Young, Q Ma, E Harbord and Ruth Oulton","doi":"10.1088/1367-2630/ad7635","DOIUrl":"https://doi.org/10.1088/1367-2630/ad7635","url":null,"abstract":"Quantum dots have the potential to be one of the brightest deterministic single photon sources with high end applications in quantum computing and cluster state generation. In this work, we re-examine the design of plain micropillars by meticulously examining the structural effects of the decay into leaky channels beyond an atom-like cavity estimation. We show that precise control of the side losses with the diameter and avoidance of propagating Bloch modes in the distributed Bragg reflectors can result in easy-to-manufacture broadband ( –2500) micropillars, allowing for broad optical coherent control pulses necessary for high single photon purity ( 99.2%–99.99% achievable) while simultaneously demonstrating extremely high efficiency out the top (90.5%–96.4%). We also demonstrate that such cavities naturally decouple from the phonon sideband, with the phonon sideband reducing by a factor of 5–33 allowing us to predict that the photons should show 98.5%–99.8% indistinguishability without the need for filtering.","PeriodicalId":19181,"journal":{"name":"New Journal of Physics","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214662","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 : 2024-09-11DOI: 10.1088/1367-2630/ad6a7d
Hyunsoo Choi, Seungman Choi, Peter Menart, Angshuman Deka and Zubin Jacob
The Rayleigh limit and low signal-to-noise ratio (SNR) scenarios pose significant limitations to optical imaging systems used in remote sensing, infrared thermal imaging, and space domain awareness. In this study, we introduce a stochastic sub-Rayleigh imaging (SSRI) algorithm to localize point objects and estimate their positions, brightnesses, and number in low SNR conditions, even below the Rayleigh limit. Our algorithm adopts a maximum likelihood approach and exploits the Poisson distribution of incoming photons to overcome the Rayleigh limit in low SNR conditions. In our experimental validation, which closely mirrors practical scenarios, we focus on conditions with closely spaced sources within the sub-Rayleigh limit (0.49–1.00 R) and weak signals (SNR less than 1.2). We use the Jaccard index and Jaccard efficiency as a figure of merit to quantify imaging performance in the sub-Rayleigh region. Our approach consistently outperforms established algorithms such as Richardson–Lucy and CLEAN by 4X in the low SNR, sub-Rayleigh regime. Our SSRI algorithm allows existing telescope-based optical/infrared imaging systems to overcome the extreme limit of sub-Rayleigh, low SNR source distributions, potentially impacting a wide range of fields, including passive thermal imaging, remote sensing, and space domain awareness.
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