Pub Date : 2024-09-09DOI: 10.1103/physreva.110.032207
Mariam Ughrelidze, Vincent P. Flynn, Emilio Cobanera, Lorenza Viola
We provide a framework for understanding dynamical metastability in open many-body systems of free bosons, whereby the dynamical stability properties of the system in the infinite-size (thermodynamic) limit may sharply differ from those of any finite-size truncation, and anomalous transient dynamics may arise. By leveraging pseudospectral techniques, we trace the discrepancy between asymptotic and transient dynamics to the non-normality of the underlying quadratic bosonic Lindbladian (QBL) generator and show that two distinct flavors of dynamical metastability can arise. QBLs exhibiting type I dynamical metastability, previously discussed in the context of anomalous transient amplification [Phys. Rev. Lett.127, 245701 (2021)], are dynamically unstable in the infinite-size limit yet stable once open boundaries are imposed. In contrast, type II dynamically metastable QBLs, which we uncover in this work, are dynamically stable for infinite size but become unstable under open boundary conditions for arbitrary finite system size. We exhibit representative models for both types of metastability in the dissipative, as well as the closed-system (Hamiltonian) settings, and analyze distinctive behavior they can engender. We show that dynamical metastability manifests itself in the generation of entanglement entropy by way of a transient which reflects the stability phase of the infinite (rather than the actual finite) system and, as a result, is directly tied to the emergence of supervolume entanglement scaling in type I systems. Finally, we demonstrate how, even in Hermitian, and especially in highly non-normal regimes, the spectral properties of an infinite-size QBL are reflected in the linear response functions of the corresponding finite QBLs by way of resonant pseudospectral modes.
我们提供了一个框架来理解自由玻色子开放多体系统的动力学陨变，在这个框架中，系统在无限大小（热力学）极限的动力学稳定性特性可能与任何有限大小截断的动力学稳定性特性截然不同，并且可能出现反常的瞬态动力学。通过利用伪谱技术，我们将渐近动力学和瞬态动力学之间的差异追溯到底层二次玻色林德布拉德（QBL）发生器的非正态性，并证明可能出现两种不同的动力学陨变。QBLs 表现出的第一类动态隐变性，以前在反常瞬态放大的背景下讨论过[Phys. Rev. Lett. 127, 245701 (2021)]，在无限大极限下动态不稳定，但一旦施加开放边界就会稳定。相反，我们在这项工作中发现的第二类动态瞬变 QBLs 在无限大时是动态稳定的，但在任意有限系统大小的开放边界条件下就变得不稳定了。我们展示了在耗散和封闭系统（哈密顿）环境中这两种类型的陨变性的代表模型，并分析了它们可能产生的独特行为。我们表明，动态陨变性表现为通过瞬态产生纠缠熵，这种瞬态反映了无限（而非实际有限）系统的稳定阶段，因此与 I 型系统中出现的超体积纠缠缩放直接相关。最后，我们证明了即使在赫米特，特别是在高度非正态分布情况下，无限大小 QBL 的频谱特性如何通过共振伪频谱模式反映在相应有限 QBL 的线性响应函数中。
{"title":"Interplay of finite- and infinite-size stability in quadratic bosonic Lindbladians","authors":"Mariam Ughrelidze, Vincent P. Flynn, Emilio Cobanera, Lorenza Viola","doi":"10.1103/physreva.110.032207","DOIUrl":"https://doi.org/10.1103/physreva.110.032207","url":null,"abstract":"We provide a framework for understanding <i>dynamical metastability</i> in open many-body systems of free bosons, whereby the dynamical stability properties of the system in the infinite-size (thermodynamic) limit may sharply differ from those of any finite-size truncation, and anomalous transient dynamics may arise. By leveraging pseudospectral techniques, we trace the discrepancy between asymptotic and transient dynamics to the <i>non-normality</i> of the underlying quadratic bosonic Lindbladian (QBL) generator and show that two distinct flavors of dynamical metastability can arise. QBLs exhibiting <i>type I dynamical metastability</i>, previously discussed in the context of anomalous transient amplification [<span>Phys. Rev. Lett.</span> <b>127</b>, 245701 (2021)], are dynamically unstable in the infinite-size limit yet stable once open boundaries are imposed. In contrast, <i>type II dynamically metastable</i> QBLs, which we uncover in this work, are dynamically stable for infinite size but become unstable under open boundary conditions for arbitrary finite system size. We exhibit representative models for both types of metastability in the dissipative, as well as the closed-system (Hamiltonian) settings, and analyze distinctive behavior they can engender. We show that dynamical metastability manifests itself in the generation of <i>entanglement entropy</i> by way of a transient which reflects the stability phase of the infinite (rather than the actual finite) system and, as a result, is directly tied to the emergence of <i>supervolume entanglement scaling</i> in type I systems. Finally, we demonstrate how, even in Hermitian, and especially in highly non-normal regimes, the spectral properties of an infinite-size QBL are reflected in the linear response functions of the corresponding finite QBLs by way of <i>resonant pseudospectral modes</i>.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"6 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205918","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 : 2024-09-09DOI: 10.1103/physreva.110.033309
Jonas von Milczewski, Richard Schmidt
We study theoretically the lifetimes of attractive and repulsive Fermi polarons, as well as the molecule at finite momentum in three dimensions. To this end, we develop a technique that allows for the computation of Green's functions in the whole complex frequency plane using exact analytical continuation within the functional renormalization group. The improved numerical stability and reduced computational cost of this method yield access to previously inaccessible momentum-dependent quasiparticle properties of low-lying excited states. While conventional approaches like the non-self-consistent -matrix approximation method cannot determine these lifetimes, we are able to find the momentum-dependent lifetime at different interaction strengths of both the attractive and repulsive polaron as well as the molecule. At weak coupling our results confirm predictions made from effective Fermi liquid theory regarding the decay of the attractive polaron, and we demonstrate that Fermi liquidlike behavior extends far into the strong-coupling regime where the attractive polaron and molecule exhibit a momentum scaling in their decay widths. Our results offer an intriguing insight into the momentum-dependent quasiparticle properties of the Fermi polaron problem, which can be measured using techniques such as Raman transfer and Ramsey interferometry.
我们从理论上研究了吸引力和排斥力费米极子以及分子在三维有限动量下的寿命。为此，我们开发了一种技术，利用函数重正化群内的精确分析延续计算整个复频平面的格林函数。这种方法提高了数值稳定性，降低了计算成本，从而获得了以前无法获得的低洼激发态的动量相关准粒子特性。传统方法（如非自洽 T 矩阵近似法）无法确定这些寿命，而我们却能在吸引极子、排斥极子和分子的不同相互作用强度下找到与动量相关的寿命。在弱耦合条件下，我们的结果证实了有效费米液体理论关于吸引力极子衰变的预测，我们还证明了费米液体般的行为一直延伸到强耦合制度，在强耦合制度下，吸引力极子和分子的衰变宽度表现出 p4 的动量缩放。我们的研究结果为费米极子问题中与动量相关的准粒子特性提供了一个有趣的视角，这些特性可以通过拉曼传递和拉姆齐干涉测量等技术进行测量。
{"title":"Momentum-dependent quasiparticle properties of the Fermi polaron from the functional renormalization group","authors":"Jonas von Milczewski, Richard Schmidt","doi":"10.1103/physreva.110.033309","DOIUrl":"https://doi.org/10.1103/physreva.110.033309","url":null,"abstract":"We study theoretically the lifetimes of attractive and repulsive Fermi polarons, as well as the molecule at finite momentum in three dimensions. To this end, we develop a technique that allows for the computation of Green's functions in the whole complex frequency plane using exact analytical continuation within the functional renormalization group. The improved numerical stability and reduced computational cost of this method yield access to previously inaccessible momentum-dependent quasiparticle properties of low-lying excited states. While conventional approaches like the non-self-consistent <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>T</mi></math>-matrix approximation method cannot determine these lifetimes, we are able to find the momentum-dependent lifetime at different interaction strengths of both the attractive and repulsive polaron as well as the molecule. At weak coupling our results confirm predictions made from effective Fermi liquid theory regarding the decay of the attractive polaron, and we demonstrate that Fermi liquidlike behavior extends far into the strong-coupling regime where the attractive polaron and molecule exhibit a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>p</mi><mn>4</mn></msup></math> momentum scaling in their decay widths. Our results offer an intriguing insight into the momentum-dependent quasiparticle properties of the Fermi polaron problem, which can be measured using techniques such as Raman transfer and Ramsey interferometry.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205873","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 : 2024-09-09DOI: 10.1103/physreva.110.033708
Tiemo Landes, Brian J. Smith, Michael G. Raymer
We closely replicated and extended a recent experiment [Phys. Rev. Lett.129, 183601 (2022)] that reportedly observed enhancement of two-photon-absorption rates in molecular samples by using time-frequency-entangled photon pairs, and we found that in the low-flux regime, where such enhancement is theoretically predicted in principle, the two-photon fluorescence signal is below the detection threshold using current state-of-the-art methods. The results are important in the context of efforts to enable quantum-enhanced molecular spectroscopy and imaging at ultra-low optical flux. Using an optical parametric down-conversion photon-pair source that can be varied from the low-gain spontaneous regime to the high-gain squeezing regime, we observed two-photon-induced fluorescence in the high-gain regime, but in the low-gain regime any fluorescence was below detection threshold. We supplemented the molecular fluorescence experiments with a study of nonlinear-optical sum-frequency generation, for which we are able to observe the low-to-high-gain crossover, thereby verifying our theoretical models and experimental techniques. The observed rates (or lack thereof) in both experiments are consistent with theoretical predictions and with our previous experiments, and indicate that time-frequency photon entanglement does not provide a practical means to enhance in-solution molecular two-photon fluorescence spectroscopy or imaging with current techniques.
我们密切复制并扩展了最近的一项实验[Phys. Rev. Lett. 129, 183601 (2022)]，据报道，该实验通过使用时频纠缠光子对观测到了分子样品中双光子吸收率的增强，而且我们发现，在理论上原则上可以预测这种增强的低通量体系中，双光子荧光信号低于目前最先进方法的检测阈值。这些结果对于实现超低光通量下的量子增强分子光谱学和成像具有重要意义。我们使用了一种可从低增益自发机制到高增益挤压机制变化的光学参数下转换光子对源，在高增益机制下观察到了双光子诱导荧光，但在低增益机制下，任何荧光都低于检测阈值。在分子荧光实验的基础上，我们还对非线性光学和频发生进行了研究，观察到了低增益到高增益的交叉，从而验证了我们的理论模型和实验技术。在这两项实验中观察到的速率（或缺乏速率）与理论预测和我们之前的实验一致，并表明时频光子纠缠并不能为利用现有技术增强溶液中分子双光子荧光光谱或成像提供实用的方法。
{"title":"Limitations in fluorescence-detected entangled two-photon-absorption experiments: Exploring the low- to high-gain squeezing regimes","authors":"Tiemo Landes, Brian J. Smith, Michael G. Raymer","doi":"10.1103/physreva.110.033708","DOIUrl":"https://doi.org/10.1103/physreva.110.033708","url":null,"abstract":"We closely replicated and extended a recent experiment [<span>Phys. Rev. Lett.</span> <b>129</b>, 183601 (2022)] that reportedly observed enhancement of two-photon-absorption rates in molecular samples by using time-frequency-entangled photon pairs, and we found that in the low-flux regime, where such enhancement is theoretically predicted in principle, the two-photon fluorescence signal is below the detection threshold using current state-of-the-art methods. The results are important in the context of efforts to enable quantum-enhanced molecular spectroscopy and imaging at ultra-low optical flux. Using an optical parametric down-conversion photon-pair source that can be varied from the low-gain spontaneous regime to the high-gain squeezing regime, we observed two-photon-induced fluorescence in the high-gain regime, but in the low-gain regime any fluorescence was below detection threshold. We supplemented the molecular fluorescence experiments with a study of nonlinear-optical sum-frequency generation, for which we are able to observe the low-to-high-gain crossover, thereby verifying our theoretical models and experimental techniques. The observed rates (or lack thereof) in both experiments are consistent with theoretical predictions and with our previous experiments, and indicate that time-frequency photon entanglement does not provide a practical means to enhance in-solution molecular two-photon fluorescence spectroscopy or imaging with current techniques.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"32 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205875","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 : 2024-09-09DOI: 10.1103/physreva.110.032407
Zihang Wang, Dirk Bouwmeester
Diagrammatic techniques simplify a weakly interacting many-body problem into an effective few-quasiparticle problem within a system of interest (SOI). If scattering events, mediated by a bath, between those quasiparticles can be approximated as density-density interactions, the bath behaves like an effective external potential. On the other hand, exchange interactions could entangle those quasiparticles and the bath, leading to an open quantum system that induces quantum decoherence and spectral broadening. We investigate the renormalized interaction between the SOI and the bath, employing a projection operator technique similar to the one used in the Nakajima-Zwanzig method. We find that the frequency variation of this renormalized interaction is analogous to the quasiparticle residue and provides a measure of the SOI-bath separability that serves as the lower bound of the SOI-bath entanglement entropy. In the weak-coupling regime and continuum limit, we demonstrate that the degree of SOI-bath separability corresponds to the quasiparticle spectral weight in the single-impurity Anderson model and find that the loss of quantum information to the continuum of the bath can be understood as a decay process where an initial single-impurity state escapes to a thermal bath. This work provides a direction for connecting energy dissipation in quasiparticles propagation to the loss of quantum information in open quantum systems.
图解技术可将弱相互作用多体问题简化为相关系统（SOI）内的有效少准粒子问题。如果这些准粒子之间由浴介导的散射事件可以近似为密度-密度相互作用，那么浴的行为就像一个有效的外部势能。另一方面，交换相互作用可能会缠结这些准粒子和浴槽，从而导致一个开放的量子系统，诱发量子退相干和光谱展宽。我们采用与中岛-茨万齐格（Nakajima-Zwanzig）方法类似的投影算子技术，研究了 SOI 与熔池之间的重正化相互作用。我们发现，这种重规范化相互作用的频率变化类似于准粒子残差，并提供了 SOI 与浴分离性的量度，可作为 SOI 与浴纠缠熵的下限。在弱耦合体系和连续极限中，我们证明了 SOI-浴分离度对应于单纯度安德森模型中的类粒子谱权，并发现量子信息在浴连续中的损失可以理解为初始单纯度态逃逸到热浴中的衰变过程。这项工作为将类粒子传播中的能量耗散与开放量子系统中的量子信息丢失联系起来提供了一个方向。
{"title":"Correspondence between quasiparticle dissipation and quantum information decay in open quantum systems","authors":"Zihang Wang, Dirk Bouwmeester","doi":"10.1103/physreva.110.032407","DOIUrl":"https://doi.org/10.1103/physreva.110.032407","url":null,"abstract":"Diagrammatic techniques simplify a weakly interacting many-body problem into an effective few-quasiparticle problem within a system of interest (SOI). If scattering events, mediated by a bath, between those quasiparticles can be approximated as density-density interactions, the bath behaves like an effective external potential. On the other hand, exchange interactions could entangle those quasiparticles and the bath, leading to an open quantum system that induces quantum decoherence and spectral broadening. We investigate the renormalized interaction between the SOI and the bath, employing a projection operator technique similar to the one used in the Nakajima-Zwanzig method. We find that the frequency variation of this renormalized interaction is analogous to the quasiparticle residue and provides a measure of the SOI-bath separability that serves as the lower bound of the SOI-bath entanglement entropy. In the weak-coupling regime and continuum limit, we demonstrate that the degree of SOI-bath separability corresponds to the quasiparticle spectral weight in the single-impurity Anderson model and find that the loss of quantum information to the continuum of the bath can be understood as a decay process where an initial single-impurity state escapes to a thermal bath. This work provides a direction for connecting energy dissipation in quasiparticles propagation to the loss of quantum information in open quantum systems.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"45 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205922","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 : 2024-09-09DOI: 10.1103/physreva.110.033707
Wenju Gu, Tao Li, Ye Tian, Zhen Yi, Gao-xiang Li
We investigate one- and two-photon scattering in a one-dimensional waveguide coupled to a giant atom within the non-Markovian regime using the resolvent approach. The non-Markovian behavior gives rise to an atom-photon bound state that cannot be excited by a single incident photon. However, the bound state can be excited via the two-photon scattering process described by multichannel scattering theory, from which an analytical trapping probability of a photon in the bound state can be achieved. Additionally, we analyze the two-photon scattering process, obtaining the analytical expressions for scattered states. As non-Markovian effects strengthen, two peaks appear in the incoherent power spectrum, attributed to the system behaving as a leaky cavity formed by the giant atom's coupling points. Through the analysis of second-order correlation functions, we observe the bunching behavior for transmitted photons, antibunching behavior for reflected photons, and the distinctive retrieval behavior at the coupling points' separation.
{"title":"Two-photon dynamics in non-Markovian waveguide QED with a giant atom","authors":"Wenju Gu, Tao Li, Ye Tian, Zhen Yi, Gao-xiang Li","doi":"10.1103/physreva.110.033707","DOIUrl":"https://doi.org/10.1103/physreva.110.033707","url":null,"abstract":"We investigate one- and two-photon scattering in a one-dimensional waveguide coupled to a giant atom within the non-Markovian regime using the resolvent approach. The non-Markovian behavior gives rise to an atom-photon bound state that cannot be excited by a single incident photon. However, the bound state can be excited via the two-photon scattering process described by multichannel scattering theory, from which an analytical trapping probability of a photon in the bound state can be achieved. Additionally, we analyze the two-photon scattering process, obtaining the analytical expressions for scattered states. As non-Markovian effects strengthen, two peaks appear in the incoherent power spectrum, attributed to the system behaving as a leaky cavity formed by the giant atom's coupling points. Through the analysis of second-order correlation functions, we observe the bunching behavior for transmitted photons, antibunching behavior for reflected photons, and the distinctive retrieval behavior at the coupling points' separation.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"15 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205874","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 : 2024-09-09DOI: 10.1103/physreva.110.l030803
Phillip C. Lotshaw, Brian C. Sawyer, Creston D. Herold, Gilles Buchs
We analytically solve a model for light scattering in Ising dynamics of metastable atomic qubits, generalizing the approach of Foss-Feig et al. [Phys. Rev. A87, 042101 (2013)] to include leakage outside the qubit manifold. We analyze the influence of these fundamental errors in simulations of proposed experiments with metastable levels of ions in a Penning trap. We find that “effective magnetic fields” generated by leaked qubits have significant impacts on spin-spin correlation functions for Greenberger-Horne-Zeilinger state preparation or for quantum simulations with strong coupling, while spin squeezing uses a much weaker coupling and is largely insensitive to the simulated leakage errors, even with a few hundred ions. Our theory and results are expected to be useful in modeling a variety of metastable qubit experiments in the future.
{"title":"Exactly solvable model of light-scattering errors in quantum simulations with metastable trapped-ion qubits","authors":"Phillip C. Lotshaw, Brian C. Sawyer, Creston D. Herold, Gilles Buchs","doi":"10.1103/physreva.110.l030803","DOIUrl":"https://doi.org/10.1103/physreva.110.l030803","url":null,"abstract":"We analytically solve a model for light scattering in Ising dynamics of metastable atomic qubits, generalizing the approach of Foss-Feig <i>et al.</i> [<span>Phys. Rev. A</span> <b>87</b>, 042101 (2013)] to include leakage outside the qubit manifold. We analyze the influence of these fundamental errors in simulations of proposed experiments with metastable levels of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><none></none><mo>+</mo><mprescripts></mprescripts><none></none><mn>40</mn></mmultiscripts></math> ions in a Penning trap. We find that “effective magnetic fields” generated by leaked qubits have significant impacts on spin-spin correlation functions for Greenberger-Horne-Zeilinger state preparation or for quantum simulations with strong coupling, while spin squeezing uses a much weaker coupling and is largely insensitive to the simulated leakage errors, even with a few hundred ions. Our theory and results are expected to be useful in modeling a variety of metastable qubit experiments in the future.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"7 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205877","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 : 2024-09-09DOI: 10.1103/physreva.110.033706
Seyyed Hossein Asadpour, Muqaddar Abbas, Hamid R. Hamedi, Julius Ruseckas, Emmanuel Paspalakis, Reza Asgari
We propose a scheme aimed at achieving spatiospectral control over spontaneous emission within a four-level atom-light coupling system interacting with optical vortices carrying orbital angular momentum (OAM). The atom comprises a ground level and two excited states coupled with two laser fields, forming a V subsystem where the upper states exclusively decay to a common fourth state via two channels. By investigating various initial states of the atom and considering the presence or absence of quantum interference in spontaneous emission channels, we analyze how the characteristics of the OAM-carrying vortex beam imprint onto the emission spectrum. The interplay between the optical vortex and the quantum system, including its environment modes, induces a wide variety of spatiospectral behavior, including two-dimensional spectral-peak narrowing, spectral-peak enhancement, spectral-peak suppression, and spontaneous emission reduction or quenching in the spatial azimuthal plane. Our findings shed light on the dynamics of atom–vortex-beam light interactions and offer insights into the manipulation of emission properties at the quantum level.
我们提出了一种方案，旨在实现对与携带轨道角动量（OAM）的光漩涡相互作用的四级原子光耦合系统内自发辐射的时谱控制。原子由一个基态和两个激发态组成，并与两个激光场耦合，形成一个 V 子系统，其中上层态通过两个通道衰减到共同的第四态。通过研究原子的各种初始状态，并考虑自发辐射通道中是否存在量子干扰，我们分析了携带 OAM 的涡旋光束的特性是如何印刻到发射光谱上的。光学漩涡与量子系统（包括其环境模式）之间的相互作用诱发了各种各样的空间光谱行为，包括二维光谱峰缩小、光谱峰增强、光谱峰抑制以及空间方位面上的自发辐射减少或淬灭。我们的发现揭示了原子-涡旋-光束光相互作用的动力学，并为在量子水平上操纵发射特性提供了启示。
{"title":"Spatiospectral control of spontaneous emission","authors":"Seyyed Hossein Asadpour, Muqaddar Abbas, Hamid R. Hamedi, Julius Ruseckas, Emmanuel Paspalakis, Reza Asgari","doi":"10.1103/physreva.110.033706","DOIUrl":"https://doi.org/10.1103/physreva.110.033706","url":null,"abstract":"We propose a scheme aimed at achieving spatiospectral control over spontaneous emission within a four-level atom-light coupling system interacting with optical vortices carrying orbital angular momentum (OAM). The atom comprises a ground level and two excited states coupled with two laser fields, forming a V subsystem where the upper states exclusively decay to a common fourth state via two channels. By investigating various initial states of the atom and considering the presence or absence of quantum interference in spontaneous emission channels, we analyze how the characteristics of the OAM-carrying vortex beam imprint onto the emission spectrum. The interplay between the optical vortex and the quantum system, including its environment modes, induces a wide variety of spatiospectral behavior, including two-dimensional spectral-peak narrowing, spectral-peak enhancement, spectral-peak suppression, and spontaneous emission reduction or quenching in the spatial azimuthal plane. Our findings shed light on the dynamics of atom–vortex-beam light interactions and offer insights into the manipulation of emission properties at the quantum level.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"7 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205928","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 : 2024-09-09DOI: 10.1103/physreva.110.033513
B. Anghinoni, M. Partanen, N. G. C. Astrath
We report on the continuity equations for linear momentum and energy associated to a recently introduced electromagnetic formulation based on classical dipolar sources [Eur. Phys. J. Plus138, 1034 (2023)]. When connected to the mass-polariton quasi-particle dynamics, these equations provide a consistent microscopic description of the local optical energy and momentum transfer inside dielectric media, called microscopic mass-polariton formulation. This procedure also unveils the true microscopic origin of the long-known Abraham optical force density as an interplay between induced dipoles and mechanical stresses generated within the material.
{"title":"Local model for the optical energy and momentum transfer in dielectric media and the microscopic origin of Abraham's force density","authors":"B. Anghinoni, M. Partanen, N. G. C. Astrath","doi":"10.1103/physreva.110.033513","DOIUrl":"https://doi.org/10.1103/physreva.110.033513","url":null,"abstract":"We report on the continuity equations for linear momentum and energy associated to a recently introduced electromagnetic formulation based on classical dipolar sources [<span>Eur. Phys. J. Plus</span> <b>138</b>, 1034 (2023)]. When connected to the mass-polariton quasi-particle dynamics, these equations provide a consistent microscopic description of the local optical energy and momentum transfer inside dielectric media, called microscopic mass-polariton formulation. This procedure also unveils the true microscopic origin of the long-known Abraham optical force density as an interplay between induced dipoles and mechanical stresses generated within the material.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"28 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205927","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 : 2024-09-09DOI: 10.1103/physreva.110.032208
Ladislav Mišta, Jr., Matouš Mišta, Zdeněk Hradil
The quantum rotor represents, after the harmonic oscillator, the next obvious quantum system to study the complementary pair of variables: the angular momentum and the unitary shift operator in angular momentum. Proper quantification of uncertainties and the incompatibility of these two operators are thus essential for applications of rotorlike quantum systems. While angular momentum uncertainty is characterized by variance, several uncertainty measures have been proposed for the shift operator, with dispersion the simplest example. We establish a hierarchy of those measures and corresponding uncertainty relations which are all perfectly or almost perfectly saturated by a tomographically complete set of von Mises states. Building on the interpretation of dispersion as the moment of inertia of the unit ring we then show that the other measures also possess the same mechanical interpretation. This unifying perspective allows us to express all measures as a particular instance of a single generic angular uncertainty measure. The importance of these measures is then highlighted by applying the simplest two of them to derive optimal simultaneous measurements of the angular momentum and the shift operator. Finally, we argue that the model of quantum rotor extends beyond its mechanical meaning with promising applications in the fields of singular optics, superconductive circuits with a Josephson junction, or optimal pulse shaping in the time-frequency domain. Our findings lay the groundwork for quantum-information and metrological applications of the quantum rotor and point to its interdisciplinary nature.
{"title":"Unifying uncertainties for rotorlike quantum systems","authors":"Ladislav Mišta, Jr., Matouš Mišta, Zdeněk Hradil","doi":"10.1103/physreva.110.032208","DOIUrl":"https://doi.org/10.1103/physreva.110.032208","url":null,"abstract":"The quantum rotor represents, after the harmonic oscillator, the next obvious quantum system to study the complementary pair of variables: the angular momentum and the unitary shift operator in angular momentum. Proper quantification of uncertainties and the incompatibility of these two operators are thus essential for applications of rotorlike quantum systems. While angular momentum uncertainty is characterized by variance, several uncertainty measures have been proposed for the shift operator, with dispersion the simplest example. We establish a hierarchy of those measures and corresponding uncertainty relations which are all perfectly or almost perfectly saturated by a tomographically complete set of von Mises states. Building on the interpretation of dispersion as the moment of inertia of the unit ring we then show that the other measures also possess the same mechanical interpretation. This unifying perspective allows us to express all measures as a particular instance of a single generic angular uncertainty measure. The importance of these measures is then highlighted by applying the simplest two of them to derive optimal simultaneous measurements of the angular momentum and the shift operator. Finally, we argue that the model of quantum rotor extends beyond its mechanical meaning with promising applications in the fields of singular optics, superconductive circuits with a Josephson junction, or optimal pulse shaping in the time-frequency domain. Our findings lay the groundwork for quantum-information and metrological applications of the quantum rotor and point to its interdisciplinary nature.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"7 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205919","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 : 2024-09-09DOI: 10.1103/physreva.110.032408
Chandrima B. Pushpan, Harikrishnan K J, Prithvi Narayan, Amit Kumar Pal
We consider the isotropic Heisenberg model in a magnetic field in the strong-rung-coupling limit on a two-dimensional (2D) rectangular zig-zag lattice of arbitrary size, and determine the one-dimensional (1D) effective model representing the low-energy manifold of the 2D model up to second order in perturbation theory. We consider a number of Hermitian operators defined on the Hilbert space of the 2D model, and systematically work out their action on the low-energy manifold, which are operators on the Hilbert space of the 1D effective model. For a class of operators among them, we demonstrate that the expectation values computed in the low-energy manifold of the 2D model can be mimicked by the expectation values of the corresponding operators in the 1D effective model even beyond the perturbation regime of the system parameters. We further argue that quantitatively estimating partial trace-based measures of entanglement in the 2D model may be done in the same fashion only in the perturbation regime. Our results and approach are expected to be useful in investigating observables and entanglement in the 2D models with large system sizes due to the advantage of using the effective 1D model with a smaller Hilbert space as a proxy.
{"title":"Estimating correlations and entanglement in the two-dimensional Heisenberg model in the strong-rung-coupling limit","authors":"Chandrima B. Pushpan, Harikrishnan K J, Prithvi Narayan, Amit Kumar Pal","doi":"10.1103/physreva.110.032408","DOIUrl":"https://doi.org/10.1103/physreva.110.032408","url":null,"abstract":"We consider the isotropic Heisenberg model in a magnetic field in the strong-rung-coupling limit on a two-dimensional (2D) rectangular zig-zag lattice of arbitrary size, and determine the one-dimensional (1D) effective model representing the low-energy manifold of the 2D model up to second order in perturbation theory. We consider a number of Hermitian operators defined on the Hilbert space of the 2D model, and systematically work out their action on the low-energy manifold, which are operators on the Hilbert space of the 1D effective model. For a class of operators among them, we demonstrate that the expectation values computed in the low-energy manifold of the 2D model can be mimicked by the expectation values of the corresponding operators in the 1D effective model even beyond the perturbation regime of the system parameters. We further argue that quantitatively estimating partial trace-based measures of entanglement in the 2D model may be done in the same fashion only in the perturbation regime. Our results and approach are expected to be useful in investigating observables and entanglement in the 2D models with large system sizes due to the advantage of using the effective 1D model with a smaller Hilbert space as a proxy.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"147 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205923","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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