Pub Date : 2024-07-26DOI: 10.1103/physreva.110.012620
Aparajita Bhattacharyya, Ahana Ghoshal, Ujjwal Sen
We find that a quantum device having an accessory involving precision measurement can have an enhancement of its metrological precision in estimating an unknown parameter of the quantum system by insertion of glassy disorder, accidental or engineered. We clearly mention how an unbiased estimator can also be identified in a disordered situation and how the precision thereof can be bounded by the quantum Crámer-Rao inequality. We compare the Fisher information-based lower bound of the minimum standard deviation of an unbiased estimator, in the presence of glassy disorder in the system, with the same of an ideal, viz. disorder-free, situation. The phenomenon can boost the efficiency of certain measuring devices, such as atomic clocks. The precision of these clocks, when measuring time, hinges on the precise determination of the frequency of a two-level atom. In cases where impurities are present in the atom, and can be modeled as a disorder parameter, it is possible for the measurement of frequency to be more accurate than in an ideal, disorder-free scenario. Moreover, disorder insertion can reduce the requirement of entanglement content of the initial probes, which are copies of two-qubit states, along with providing a disorder-induced enhancement.
{"title":"Enhancing precision of atomic clocks by tuning disorder in accessories","authors":"Aparajita Bhattacharyya, Ahana Ghoshal, Ujjwal Sen","doi":"10.1103/physreva.110.012620","DOIUrl":"https://doi.org/10.1103/physreva.110.012620","url":null,"abstract":"We find that a quantum device having an accessory involving precision measurement can have an enhancement of its metrological precision in estimating an unknown parameter of the quantum system by insertion of glassy disorder, accidental or engineered. We clearly mention how an unbiased estimator can also be identified in a disordered situation and how the precision thereof can be bounded by the quantum Crámer-Rao inequality. We compare the Fisher information-based lower bound of the minimum standard deviation of an unbiased estimator, in the presence of glassy disorder in the system, with the same of an ideal, viz. disorder-free, situation. The phenomenon can boost the efficiency of certain measuring devices, such as atomic clocks. The precision of these clocks, when measuring time, hinges on the precise determination of the frequency of a two-level atom. In cases where impurities are present in the atom, and can be modeled as a disorder parameter, it is possible for the measurement of frequency to be more accurate than in an ideal, disorder-free scenario. Moreover, disorder insertion can reduce the requirement of entanglement content of the initial probes, which are copies of two-qubit states, along with providing a disorder-induced enhancement.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779272","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 : 2024-07-26DOI: 10.1103/physreva.110.013714
Filippus S. Roux
Heralding, which is often used for preparing quantum optical states, is studied to determine the effects of the spatiotemporal properties of the process. Incorporating all the spatiotemporal degrees of freedom, we follow a Wigner functional approach to consider cases where these states are prepared to have Wigner functionals with negative regions, being suitable resources for quantum information technologies. General expressions are derived for single-photon-subtracted and single-photon-added states. As examples, we consider the photon-subtracted squeezed vacuum state, the photon-added coherent state, the photon-added thermal state, and the photon-added squeezed vacuum state. The Wigner functional approach reveals the importance of the spatiotemporal transformations imposed by the experimental conditions.
{"title":"Spatiotemporal effects in heralded state preparation","authors":"Filippus S. Roux","doi":"10.1103/physreva.110.013714","DOIUrl":"https://doi.org/10.1103/physreva.110.013714","url":null,"abstract":"Heralding, which is often used for preparing quantum optical states, is studied to determine the effects of the spatiotemporal properties of the process. Incorporating all the spatiotemporal degrees of freedom, we follow a Wigner functional approach to consider cases where these states are prepared to have Wigner functionals with negative regions, being suitable resources for quantum information technologies. General expressions are derived for single-photon-subtracted and single-photon-added states. As examples, we consider the photon-subtracted squeezed vacuum state, the photon-added coherent state, the photon-added thermal state, and the photon-added squeezed vacuum state. The Wigner functional approach reveals the importance of the spatiotemporal transformations imposed by the experimental conditions.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779276","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 : 2024-07-26DOI: 10.1103/physreva.110.012227
Akash Mitra, Shashi C. L. Srivastava
We study the energy-transfer process in the recently proposed sunburst quantum Ising model, which consists of two interacting integrable systems: a transverse Ising chain with a very small transverse field and a finite number of external isolated qubits. We show that in this model of the quantum battery, coupling between the battery and charger can be used to optimize the ergotropy, which is the maximum amount of energy that can be extracted from the battery. At the same time, maximum charging power increases with the coupling strength, allowing for the simultaneous optimization of both ergotropy and charging power in the strong-coupling limit. Furthermore, we show that both ergotropy and charging power are independent of the initial state of the charger.
{"title":"Sunburst quantum Ising battery","authors":"Akash Mitra, Shashi C. L. Srivastava","doi":"10.1103/physreva.110.012227","DOIUrl":"https://doi.org/10.1103/physreva.110.012227","url":null,"abstract":"We study the energy-transfer process in the recently proposed sunburst quantum Ising model, which consists of two interacting integrable systems: a transverse Ising chain with a very small transverse field and a finite number of external isolated qubits. We show that in this model of the quantum battery, coupling between the battery and charger can be used to optimize the ergotropy, which is the maximum amount of energy that can be extracted from the battery. At the same time, maximum charging power increases with the coupling strength, allowing for the simultaneous optimization of both ergotropy and charging power in the strong-coupling limit. Furthermore, we show that both ergotropy and charging power are independent of the initial state of the charger.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779117","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 : 2024-07-26DOI: 10.1103/physreva.110.012621
Patrick Tritschler, Torsten Ohms, André Zimmermann, Fabian Zschocke, Thomas Strohm, Peter Degenfeld-Schonburg
This paper discusses the possibility of using two-mode squeezed light to improve the performance of existing sensor technology with the focus on its miniaturization under realistic losses. Therefore, we analyze a system consisting of a part for two-mode squeezed light generation, a sensor region, and a detection stage. Based on a general four-wave mixing (FWM) Hamiltonian caused by third-order susceptibility, we formulate linearized equations that describe the FWM process below the threshold and are used to analyze the squeezing quality of the generated optical signal and idler modes. For a possible realization, the focus is set on chip-integrated generation using microring resonators. To do so, the impacts of the design and the pump light are considered in the derived equations. These equations are used to analyze the usage of two-mode squeezed light in quantum metrology and the application in a Mach-Zehnder interferometer. Due to the impact of losses in realistic use cases, we show that the main usage is for small and compact devices, which can lead to a quantum improvement of up to a factor of 10 in comparison with using coherent light only. This enables the use of small squeezing-enhanced sensors with a performance comparable to larger classical sensors.
{"title":"Optical interferometer using two-mode squeezed light for enhanced chip-integrated quantum metrology","authors":"Patrick Tritschler, Torsten Ohms, André Zimmermann, Fabian Zschocke, Thomas Strohm, Peter Degenfeld-Schonburg","doi":"10.1103/physreva.110.012621","DOIUrl":"https://doi.org/10.1103/physreva.110.012621","url":null,"abstract":"This paper discusses the possibility of using two-mode squeezed light to improve the performance of existing sensor technology with the focus on its miniaturization under realistic losses. Therefore, we analyze a system consisting of a part for two-mode squeezed light generation, a sensor region, and a detection stage. Based on a general four-wave mixing (FWM) Hamiltonian caused by third-order susceptibility, we formulate linearized equations that describe the FWM process below the threshold and are used to analyze the squeezing quality of the generated optical signal and idler modes. For a possible realization, the focus is set on chip-integrated generation using microring resonators. To do so, the impacts of the design and the pump light are considered in the derived equations. These equations are used to analyze the usage of two-mode squeezed light in quantum metrology and the application in a Mach-Zehnder interferometer. Due to the impact of losses in realistic use cases, we show that the main usage is for small and compact devices, which can lead to a quantum improvement of up to a factor of 10 in comparison with using coherent light only. This enables the use of small squeezing-enhanced sensors with a performance comparable to larger classical sensors.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779120","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 : 2024-07-26DOI: 10.1103/physreva.110.012619
Nada Ali, Mark Hillery
Quantum sensor networks have often been studied in order to determine how accurately they can determine a parameter, such as the strength of a magnetic field, at one of the detectors. A more coarse-grained approach is to try to simply determine whether a detector has interacted with a signal or not, and which detector it was. Such discrete-outcome quantum sensor networks, discrete in the sense that we are seeking answers to yes-no questions, are what we study here. One issue is what is a good initial state for the network, and, in particular, should it be entangled or not. Earlier we looked at the case when only one detector interacted, and here we extend that study in two ways. First, we allow more than one detector to interact, and second, we examine the effect of grouping the detectors. When the detectors are grouped we are only interested in which group contained interacting detectors and not in which individual detectors within a group interacted. We find that in the case of grouping detectors, entangled initial states can be helpful.
{"title":"Discrete-outcome sensor networks. II. Multiple detection events and grouping detectors","authors":"Nada Ali, Mark Hillery","doi":"10.1103/physreva.110.012619","DOIUrl":"https://doi.org/10.1103/physreva.110.012619","url":null,"abstract":"Quantum sensor networks have often been studied in order to determine how accurately they can determine a parameter, such as the strength of a magnetic field, at one of the detectors. A more coarse-grained approach is to try to simply determine whether a detector has interacted with a signal or not, and which detector it was. Such discrete-outcome quantum sensor networks, discrete in the sense that we are seeking answers to yes-no questions, are what we study here. One issue is what is a good initial state for the network, and, in particular, should it be entangled or not. Earlier we looked at the case when only one detector interacted, and here we extend that study in two ways. First, we allow more than one detector to interact, and second, we examine the effect of grouping the detectors. When the detectors are grouped we are only interested in which group contained interacting detectors and not in which individual detectors within a group interacted. We find that in the case of grouping detectors, entangled initial states can be helpful.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779118","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 : 2024-07-26DOI: 10.1103/physreva.110.012810
Xiao-Qiu Qi, Pei-Pei Zhang, Zong-Chao Yan, G. W. F. Drake, Ai-Xi Chen, Zhen-Xiang Zhong, Ting-Yun Shi
Standard perturbation theory in quantum mechanics is employed to calculate the mass shifts of and transitions in ions. These mass shifts are determined with high precision, typically having uncertainties of 1–2 ppm. The sensitivity of the isotope shifts between and to differences in nuclear charge radii is examined. Moreover, we present the fine-structure splitting isotope shifts, which serve as valuable tools for testing the consistency of experimental results. The study presented here will provide valuable insights for future measurements aimed at extracting atomic physics values of Be nuclear charge radii differences with an accuracy of 5% or higher.
{"title":"Theoretical calculations for isotope shifts of Be2+7,9,10,11,12,14 ions","authors":"Xiao-Qiu Qi, Pei-Pei Zhang, Zong-Chao Yan, G. W. F. Drake, Ai-Xi Chen, Zhen-Xiang Zhong, Ting-Yun Shi","doi":"10.1103/physreva.110.012810","DOIUrl":"https://doi.org/10.1103/physreva.110.012810","url":null,"abstract":"Standard perturbation theory in quantum mechanics is employed to calculate the mass shifts of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mrow></mrow><mmultiscripts><mi>S</mi><mn>0</mn><none></none><mprescripts></mprescripts><none></none><mn>1</mn></mmultiscripts><mo>−</mo><mn>2</mn><mrow></mrow><mmultiscripts><mi>S</mi><mn>1</mn><none></none><mprescripts></mprescripts><none></none><mn>3</mn></mmultiscripts></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mrow></mrow><mmultiscripts><mi>S</mi><mn>1</mn><none></none><mprescripts></mprescripts><none></none><mn>3</mn></mmultiscripts><mo>−</mo><mn>2</mn><mrow></mrow><mmultiscripts><mi>P</mi><mi>J</mi><none></none><mprescripts></mprescripts><none></none><mn>3</mn></mmultiscripts></mrow></math> transitions in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Be</mi><none></none><mrow><mn>2</mn><mo>+</mo></mrow><mprescripts></mprescripts><none></none><mrow><mn>7</mn><mo>,</mo><mn>9</mn><mo>,</mo><mn>10</mn><mo>,</mo><mn>11</mn><mo>,</mo><mn>12</mn><mo>,</mo><mn>14</mn></mrow></mmultiscripts></math> ions. These mass shifts are determined with high precision, typically having uncertainties of 1–2 ppm. The sensitivity of the isotope shifts between <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Be</mi><none></none><mrow><mn>2</mn><mo>+</mo></mrow><mprescripts></mprescripts><none></none><mrow><mn>7</mn><mo>,</mo><mn>10</mn><mo>,</mo><mn>11</mn><mo>,</mo><mn>12</mn><mo>,</mo><mn>14</mn></mrow></mmultiscripts></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Be</mi><none></none><mrow><mn>2</mn><mo>+</mo></mrow><mprescripts></mprescripts><none></none><mn>9</mn></mmultiscripts></math> to differences in nuclear charge radii is examined. Moreover, we present the fine-structure splitting isotope shifts, which serve as valuable tools for testing the consistency of experimental results. The study presented here will provide valuable insights for future measurements aimed at extracting atomic physics values of Be nuclear charge radii differences with an accuracy of 5% or higher.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779273","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 : 2024-07-25DOI: 10.1103/physreva.110.012226
Keshav Das Agarwal, Tanoy Kanti Konar, Leela Ganesh Chandra Lakkaraju, Aditi Sen(De)
Non-Hermitian rotation-time reversal -symmetric spin models possess two distinct phases, the unbroken phase in which the entire spectrum is real and the broken phase which contains complex eigenspectra, thereby indicating a transition point, referred to as an exceptional point. We report that the dynamical quantities, namely, the short- and long-time average of the Loschmidt echo, which is the overlap between the initial and the final states, and the corresponding rate function can faithfully predict the exceptional point. In particular, when the initial state is prepared as the ground state in the unbroken phase of the non-Hermitian Hamiltonian and the system is quenched to either the broken or unbroken phase, we analytically demonstrate that the rate function and the average Loschmidt echo can distinguish between the quench that occurred in the broken or the unbroken phase for the nearest-neighbor non-Hermitian model with uniform and alternating magnetic fields, thereby indicating the exceptional point. Furthermore, we exhibit that such quantities are capable of identifying the exceptional point even in models like the non-Hermitian short- and long-range model with magnetic field, which can only be solved numerically, thereby establishing it as detection criteria for recognizing exceptional points.
{"title":"Detecting exceptional points through dynamics in non-Hermitian systems","authors":"Keshav Das Agarwal, Tanoy Kanti Konar, Leela Ganesh Chandra Lakkaraju, Aditi Sen(De)","doi":"10.1103/physreva.110.012226","DOIUrl":"https://doi.org/10.1103/physreva.110.012226","url":null,"abstract":"Non-Hermitian rotation-time reversal <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>(</mo><mi mathvariant=\"script\">RT</mi><mo>)</mo></math>-symmetric spin models possess two distinct phases, the unbroken phase in which the entire spectrum is real and the broken phase which contains complex eigenspectra, thereby indicating a transition point, referred to as an exceptional point. We report that the dynamical quantities, namely, the short- and long-time average of the Loschmidt echo, which is the overlap between the initial and the final states, and the corresponding rate function can faithfully predict the exceptional point. In particular, when the initial state is prepared as the ground state in the unbroken phase of the non-Hermitian Hamiltonian and the system is quenched to either the broken or unbroken phase, we analytically demonstrate that the rate function and the average Loschmidt echo can distinguish between the quench that occurred in the broken or the unbroken phase for the nearest-neighbor non-Hermitian <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>X</mi><mi>Y</mi></mrow></math> model with uniform and alternating magnetic fields, thereby indicating the exceptional point. Furthermore, we exhibit that such quantities are capable of identifying the exceptional point even in models like the non-Hermitian short- and long-range <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>X</mi><mi>Y</mi><mi>Z</mi></mrow></math> model with magnetic field, which can only be solved numerically, thereby establishing it as detection criteria for recognizing exceptional points.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785862","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 : 2024-07-25DOI: 10.1103/physreva.110.013712
Karthik Chinni, Nicolás Quesada
We study the dynamics of the pump mode in the down-conversion Hamiltonian using the cumulant-expansion method, perturbation theory, and the full numerical simulation of systems with a pump mean photon number of up to . We particularly focus on the properties of the pump mode such as depletion, entanglement, and squeezing for an experimentally relevant initial state in which the pump mode is initialized in a coherent state. Through this analysis, we obtain the short-time behavior of various quantities and derive timescales at which the above-mentioned features, which cannot be understood through the parametric approximation, originate in the system. We also provide an entanglement witness involving moments of bosonic operators that can capture the entanglement of the pump mode. Finally, we study the photon-number statistics of the pump and the signal and idler modes to understand the general behavior of these modes for experimentally relevant timescales.
{"title":"Beyond the parametric approximation: Pump depletion, entanglement, and squeezing in macroscopic down-conversion","authors":"Karthik Chinni, Nicolás Quesada","doi":"10.1103/physreva.110.013712","DOIUrl":"https://doi.org/10.1103/physreva.110.013712","url":null,"abstract":"We study the dynamics of the pump mode in the down-conversion Hamiltonian using the cumulant-expansion method, perturbation theory, and the full numerical simulation of systems with a pump mean photon number of up to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>100</mn><mspace width=\"0.16em\"></mspace><mn>000</mn></mrow></math>. We particularly focus on the properties of the pump mode such as depletion, entanglement, and squeezing for an experimentally relevant initial state in which the pump mode is initialized in a coherent state. Through this analysis, we obtain the short-time behavior of various quantities and derive timescales at which the above-mentioned features, which cannot be understood through the parametric approximation, originate in the system. We also provide an entanglement witness involving moments of bosonic operators that can capture the entanglement of the pump mode. Finally, we study the photon-number statistics of the pump and the signal and idler modes to understand the general behavior of these modes for experimentally relevant timescales.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785864","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 : 2024-07-25DOI: 10.1103/physreva.110.012461
Alan Kahan, Cecilia Cormick
Dissipative quantum systems can under appropriate conditions exhibit bi- or multipartite entanglement at the steady state. The presence and properties of these quantum correlations depend on the relevant model parameters. Here, we characterize the steady-state entanglement in connection with the spatial structure of a small chain of three ions dispersively coupled with a pumped optical cavity. Within a semiclassical approximation, we describe the relation between entanglement, spatial organization, and vibrational modes of the ion chain. Upon increasing the pumping strength, our system undergoes a transition from a sliding to a pinned configuration, in which ions are expelled from the maxima of the optical potential. The features of the steady-state entanglement strongly depend on the kind of pinned configuration reached. We identify scenarios leading to entangled steady states, analyze the effect of defect formation upon entanglement between different system partitions, and observe the presence of multipartite quantum correlations.
{"title":"Entanglement across the sliding-pinned transition of ion chains in optical cavities","authors":"Alan Kahan, Cecilia Cormick","doi":"10.1103/physreva.110.012461","DOIUrl":"https://doi.org/10.1103/physreva.110.012461","url":null,"abstract":"Dissipative quantum systems can under appropriate conditions exhibit bi- or multipartite entanglement at the steady state. The presence and properties of these quantum correlations depend on the relevant model parameters. Here, we characterize the steady-state entanglement in connection with the spatial structure of a small chain of three ions dispersively coupled with a pumped optical cavity. Within a semiclassical approximation, we describe the relation between entanglement, spatial organization, and vibrational modes of the ion chain. Upon increasing the pumping strength, our system undergoes a transition from a sliding to a pinned configuration, in which ions are expelled from the maxima of the optical potential. The features of the steady-state entanglement strongly depend on the kind of pinned configuration reached. We identify scenarios leading to entangled steady states, analyze the effect of defect formation upon entanglement between different system partitions, and observe the presence of multipartite quantum correlations.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779109","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 : 2024-07-25DOI: 10.1103/physreva.110.013325
Ben McCanna, Hannah M. Price
The study of superfluid quantum vortices has long been an important area of research, with previous work naturally focusing on two-dimensional and three-dimensional systems, where rotation stabilizes point vortices and line vortices respectively. Interestingly, this physics generalizes for a hypothetical four-dimensional (4D) superfluid to include vortex planes, which can have a much richer phenomenology. In this paper we study the possibility of skewed and curved vortex planes, which have no direct analog in lower dimensions. By analytically and numerically studying the 4D Gross-Pitaevskii equation, we show that such vortex surfaces can be stabilized and favored by double rotation with unequal rotation frequencies. Our work raises open questions for further research into the physics of these vortex surfaces and suggests interesting future extensions to tilted vortex surfaces under equal-frequency double rotation and to more realistic 4D models.
{"title":"Curved vortex surfaces in four-dimensional superfluids. I. Unequal-frequency double rotations","authors":"Ben McCanna, Hannah M. Price","doi":"10.1103/physreva.110.013325","DOIUrl":"https://doi.org/10.1103/physreva.110.013325","url":null,"abstract":"The study of superfluid quantum vortices has long been an important area of research, with previous work naturally focusing on two-dimensional and three-dimensional systems, where rotation stabilizes point vortices and line vortices respectively. Interestingly, this physics generalizes for a hypothetical four-dimensional (4D) superfluid to include vortex planes, which can have a much richer phenomenology. In this paper we study the possibility of skewed and curved vortex planes, which have no direct analog in lower dimensions. By analytically and numerically studying the 4D Gross-Pitaevskii equation, we show that such vortex surfaces can be stabilized and favored by double rotation with unequal rotation frequencies. Our work raises open questions for further research into the physics of these vortex surfaces and suggests interesting future extensions to tilted vortex surfaces under equal-frequency double rotation and to more realistic 4D models.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779104","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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