Physical Review A最新文献

{"title":"Combined microwave and optical spectroscopy for hyperfine structure analysis in thulium atoms","authors":"Denis Mishin, Dmitry Tregubov, Nikolay Kolachevsky, Artem Golovizin","doi":"10.1103/physreva.110.032817","DOIUrl":"https://doi.org/10.1103/physreva.110.032817","url":null,"abstract":"We present refined values of the hyperfine splitting frequencies of the ground <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mrow><mo>|</mo><mi>g</mi><mo>〉</mo></mrow><mo>=</mo><mrow><mrow><mo>|</mo></mrow><mrow><mn>4</mn><msup><mi>f</mi><mn>13</mn></msup><mrow><msup><mo>(</mo><mn>2</mn></msup><msup><mi>F</mi><mi>o</mi></msup><mo>)</mo></mrow><mn>6</mn><msup><mi>s</mi><mn>2</mn></msup><mo>,</mo><mi>J</mi><mo>=</mo><mn>7</mn><mo>/</mo><mn>2</mn></mrow><mrow><mo>〉</mo></mrow></mrow></mrow></math> and clock <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mrow><mo>|</mo><mi>c</mi><mo>〉</mo></mrow><mo>=</mo><mrow><mrow><mo>|</mo></mrow><mrow><mn>4</mn><msup><mi>f</mi><mn>13</mn></msup><mrow><msup><mo>(</mo><mn>2</mn></msup><msup><mi>F</mi><mi>o</mi></msup><mo>)</mo></mrow><mn>6</mn><msup><mi>s</mi><mn>2</mn></msup><mo>,</mo><mi>J</mi><mo>=</mo><mn>5</mn><mo>/</mo><mn>2</mn></mrow><mrow><mo>〉</mo></mrow></mrow></mrow></math> states of thulium atoms, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msubsup><mi>f</mi><mrow><mi>g</mi></mrow><mtext>HFS</mtext></msubsup><mo>=</mo><mn>1</mn><mspace width=\"0.16em\"></mspace><mn>496</mn><mspace width=\"0.16em\"></mspace><mn>550</mn><mspace width=\"0.16em\"></mspace><mn>658.23</mn><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mrow></math> Hz and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msubsup><mi>f</mi><mrow><mi>c</mi></mrow><mtext>HFS</mtext></msubsup><mo>=</mo><mn>2</mn><mspace width=\"0.16em\"></mspace><mn>113</mn><mspace width=\"0.16em\"></mspace><mn>946</mn><mspace width=\"0.16em\"></mspace><mn>873.08</mn><mrow><mo>(</mo><mn>9</mn><mo>)</mo></mrow></mrow></math> Hz, respectively. The measurements are performed on an ultracold atomic ensemble in an optical lattice using combined microwave and optical transition spectroscopy. The achieved measurement accuracy of less than 0.1 ppb represents an improvement of 2 and 7 orders of magnitude for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msubsup><mi>f</mi><mrow><mi>g</mi></mrow><mtext>HFS</mtext></msubsup></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msubsup><mi>f</mi><mrow><mi>c</mi></mrow><mtext>HFS</mtext></msubsup></math>, respectively, compared to the previously published values. We also refine the value of the Landé <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>g</mi></math>-factor of the clock level to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>g</mi><mi>c</mi></msub><mo>=</mo><mn>0.854</mn><mspace width=\"0.16em\"></mspace><mn>786</mn><mrow><mo>(</mo><mn>12</mn><mo>)</mo></mrow></mrow></math>. The results of this work can be used in the frequency standards and quantum simulators based on thulium atoms being developed today, as well as in a number of fundamental studies that require precise knowledge of the hyperfine structure characteristics of various elements.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"4 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262764","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}

{"title":"Spectral evidence of vibronic Rabi oscillations in the resonance-enhanced photodissociation of MgH+","authors":"Dilfuza Umarova, Otabek Umarov, Attila Tóth, András Csehi","doi":"10.1103/physreva.110.033112","DOIUrl":"https://doi.org/10.1103/physreva.110.033112","url":null,"abstract":"We study by real-time wave-packet simulations the sequential two-photon dissociation of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mrow><mi>MgH</mi></mrow><mo>+</mo></msup></math> molecule, under intense ultraviolet laser pulses of narrow spectral width. By a resonant coupling, one-photon Rabi oscillations are generated between two vibrational levels of the molecule, belonging to two different bound electronic states. These vibronic Rabi oscillations are probed upon absorption of further photons from the same laser pulse, that gradually promote the molecule to a dissociative electronic state. Calculating the energy spectrum of the photofragments explicitly analytically, we elucidate the physical origin of the main spectral features—such as the splitting, shifting, asymmetry, and multipeak pattern—identified by accurate numerical simulations. We find that the pronounced spectral intensity modulations result from the interference of fragment amplitudes that are generated during the distinct Rabi cycles in the upper and lower dynamically dressed states, formed upon the resonant coupling with the laser pulse. These intensity modulations are sensitively influenced by the resonant and nonresonant Stark effects, and can be manipulated by the parameters of the applied laser pulse. Our results contribute to the understanding and control of ultrafast coherent phenomena via the energy spectrum of particles emitted during the dynamical process under investigation.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"27 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262765","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}

{"title":"Relativistic and recoil corrections to vacuum polarization in muonic systems: Three-photon exchange, gauge invariance, and numerical values","authors":"Gregory S. Adkins, Ulrich D. Jentschura","doi":"10.1103/physreva.110.032816","DOIUrl":"https://doi.org/10.1103/physreva.110.032816","url":null,"abstract":"For an accurate theoretical description of muonic bound systems, it is crucial to consistently treat relativistic and recoil corrections to vacuum polarization. The one-loop vacuum-polarization effect is by far the dominant quantum electrodynamic (QED) energy correction for bound muons, being of order <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>α</mi><msup><mrow><mo>(</mo><mi>Z</mi><mi>α</mi><mo>)</mo></mrow><mn>2</mn></msup><msub><mi>m</mi><mi>r</mi></msub></mrow></math>, where <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>α</mi></math> is the fine-structure constant, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>Z</mi></math> is the nuclear charge number, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>m</mi><mi>r</mi></msub></math> is the reduced mass. Gauge invariance of the relativistic and recoil corrections to vacuum polarization of order <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>α</mi><msup><mrow><mo>(</mo><mi>Z</mi><mi>α</mi><mo>)</mo></mrow><mn>4</mn></msup><msub><mi>m</mi><mi>r</mi></msub></mrow></math> is investigated with respect to nonretarded and standard, renormalized variants of Coulomb gauge. The invariance is shown after including three-photon exchange diagrams. Our derivation is based on an adapted form of nonrelativistic quantum electrodynamics for bound muon systems (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NRQED</mi><mi>μ</mi></msub></math>), which is a version of NRQED where the hard scale is set at the muon mass instead of the electron mass. Updated values for the gauge-independent corrections for one-muon ions with nuclear charge numbers <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>6</mn></mrow></math> are presented.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"24 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262762","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}

{"title":"Universality and two-body losses: Lessons from the effective non-Hermitian dynamics of two particles","authors":"Alice Marché, Hironobu Yoshida, Alberto Nardin, Hosho Katsura, Leonardo Mazza","doi":"10.1103/physreva.110.033321","DOIUrl":"https://doi.org/10.1103/physreva.110.033321","url":null,"abstract":"We study the late-time dynamics of two particles confined in one spatial dimension and subject to two-body losses. The dynamics is exactly described by a non-Hermitian Hamiltonian that can be analytically studied both in the continuum and on a lattice. The asymptotic decay rate and the universal power-law form of the decay of the number of particles are exactly computed in the whole parameter space of the problem. When in the initial state the two particles are far apart, the average number of particles in the setup decays with time <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>t</mi></math> as <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>t</mi><mrow><mo>−</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math>; a different power law, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>t</mi><mrow><mo>−</mo><mn>3</mn><mo>/</mo><mn>2</mn></mrow></msup></math>, is found when the two particles overlap in the initial state. These results are valid both in the continuum and on a lattice, but in the latter case a logarithmic correction appears.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"30 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262766","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}

{"title":"Multipartite multiplexing strategies for quantum routers","authors":"Julia A. Kunzelmann, Hermann Kampermann, Dagmar Bruß","doi":"10.1103/physreva.110.032617","DOIUrl":"https://doi.org/10.1103/physreva.110.032617","url":null,"abstract":"This work explores the important role of quantum routers in communication networks and investigates the increase in efficiency using memories and multiplexing strategies. Motivated by the bipartite setup introduced by Abruzzo <i>et al.</i> [<span>Phys. Rev. A</span> <b>89</b>, 012303 (2014)] for finite-range multiplexing in quantum repeaters, we extend the study to an <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math>-partite network with a router as a central station. We present a general protocol for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math> parties after defining the underlying matching problem and we calculate the router rate for different <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math>. We analyze the improvement due to multiplexing and analyze the secret key rate with explicit results for the tripartite network. Investigating strategic qubit selection for the Greenberger-Horne-Zeilinger measurements, we show that using cutoffs to remove qubits after a certain number of rounds and consistently combining qubits with the lowest number of storage rounds leads to an optimal secret key rate.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"31 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262773","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}

{"title":"Parallel two-qubit entangling gates via a quantum nondemolition interaction controlled by rotation","authors":"E. A. Vashukevich, T. Yu. Golubeva","doi":"10.1103/physreva.110.032616","DOIUrl":"https://doi.org/10.1103/physreva.110.032616","url":null,"abstract":"The paper presents an analysis of entangling and nonlocal operations in a quantum nondemolition (QND) interaction between multimode light with orbital angular momentum and an atomic ensemble. A protocol consists of two QND operations with rotations of quadratures of atomic spin coherence and light between them. This protocol provides a wide range of two-qubit operations, while the multimode nature of the chosen degrees of freedom allows the implementation of parallel operations over multiple two-qubit systems. We have used the formalism of equivalence classes and local invariants to evaluate the properties of two-qubit transformations. It is shown that, when selecting suitable values of the governing parameters, such as the duration of each of the two QND interactions and the rotation angles of the qubits, the protocol allows to realize a deterministic nonlocal SWAP operation and entangling <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msqrt><mtext>SWAP</mtext></msqrt></math> operation with probability <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mfrac><mn>1</mn><mn>3</mn></mfrac></math>.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"27 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262772","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}

{"title":"Separation of various higher-order effects in the ionization of helium by proton impact","authors":"S. Majumdar, S. Bastola, A. Hasan, R. Lomsadze, M. Schulz","doi":"10.1103/physreva.110.032814","DOIUrl":"https://doi.org/10.1103/physreva.110.032814","url":null,"abstract":"We have measured fully differential cross sections (FDCSs) for ionization of helium by 75 keV proton impact. Data were analyzed for electrons ejected into the scattering plane at projectile energy losses well below and above the matching velocity and for scattering angles ranging between 0.1 and 0.5 mrad. Earlier, we observed clear signatures of the postcollision interaction (PCI) at the matching velocity; however, in the current data these signatures are completely absent at small energy losses and residues remain at large energy losses. At small energy losses the FDCSs are dominated by non-PCI higher-order effects.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"77 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262921","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}

{"title":"Demonstration of superior communication through thermodynamically free channels in an optical quantum switch","authors":"Hao Tang, Yu Guo, Xiao-Min Hu, Yun-Feng Huang, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo","doi":"10.1103/physreva.110.032422","DOIUrl":"https://doi.org/10.1103/physreva.110.032422","url":null,"abstract":"The release of the causal structure of physical events from a well-defined order to an indefinite order stimulates remarkable enhancements in various quantum information tasks. Some of these advantages, however, are questioned for the ambiguous role of the control system in the quantum switch, which is an experimentally realized process with an indefinite causal structure. In communications, for example, not only the superposition of alternative causal orders, but also the superposition of alternative trajectories can accelerate information transmissions. Here, we follow the proposal of Liu <i>et al.</i> [<span>Phys. Rev. Lett.</span> <b>129</b>, 230604 (2022)], and examine the information enhancement effect of indefinite causal orders with the toolkit of thermodynamics in a photonic platform. Specifically, we simulate the thermal interaction between a system qubit and two heat baths embedded in a quantum switch by implementing the corresponding switched thermal channels. Although its action on the system qubit only is thermally free, our results suggest that the quantum switch should be seen as a resource when the control qubit is also considered. Moreover, we characterize the non-Markovian property in this scenario by measuring the information backflows from the heat baths to the system qubit.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"48 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262768","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}

{"title":"Probing the position-dependent optical energy fluence rate in three-dimensional scattering samples","authors":"Ozan Akdemir, Minh Duy Truong, Alfredo Rates, Ad Lagendijk, Willem L. Vos","doi":"10.1103/physreva.110.033520","DOIUrl":"https://doi.org/10.1103/physreva.110.033520","url":null,"abstract":"The accurate determination of the position-dependent energy fluence rate of scattered light (which is proportional to the energy density) is crucial to the understanding of transport in anisotropically scattering and absorbing samples, such as biological tissue, seawater, atmospheric turbulent layers, and light-emitting diodes. While Monte Carlo simulations are precise, their long computation time is not desirable. Common analytical approximations to the radiative transfer equation (RTE) fail to predict light transport and could even give unphysical results. Therefore, we experimentally probe the position-dependent energy fluence rate of light inside scattering samples where the widely used <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>P</mi><mn>1</mn></msub></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>P</mi><mn>3</mn></msub></math> approximations to the RTE fail. The samples are three-dimensional (3D) aqueous suspensions of anisotropically scattering and both absorbing and nonabsorbing spherical scatterers, namely, microspheres (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>r</mi><mo>=</mo><mn>0.5</mn><mspace width=\"3.33333pt\"></mspace><mi>µ</mi><mi mathvariant=\"normal\">m</mi></mrow></math>) with and without absorbing dye. To probe the energy fluence rate, we detect the emission of quantum-dot reporter particles that are excited by the incident light and that are contained in a thin capillary. By scanning the capillary through the sample, we access the position dependence. We present a comprehensive discussion of experimental limitations and of both random and systematic errors. Our observations agree well with the Monte Carlo simulations and the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>P</mi><mn>3</mn></msub></math> approximation of the RTE with a correction for forward scattering. In contrast, the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>P</mi><mn>1</mn></msub></math> and the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>P</mi><mn>3</mn></msub></math> approximations deviate increasingly from our observations, ultimately even predicting unphysical negative energies.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"171 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262919","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}

{"title":"Fundamental constants from photon-photon scattering in three-beam collisions","authors":"A. J. MacLeod, B. King","doi":"10.1103/physreva.110.032216","DOIUrl":"https://doi.org/10.1103/physreva.110.032216","url":null,"abstract":"Direct measurement of the elastic scattering of real photons on an electromagnetic field would allow the fundamental low-energy constants of quantum electrodynamics to be experimentally determined. We show that scenarios involving the collision of three laser beams have several advantages over conventional two-beam scenarios. The kinematics of a three-beam collision allows for a higher signal-to-background ratio in the detection region, without the need for polarimetry, and separates out contributions from different orders of photon scattering. A planar configuration of colliding a photon beam from an x-ray free-electron laser with two optical beams is studied in detail. We show that measurements of elastic photon scattering and vacuum birefringence are possible with currently available technology.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"3 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262771","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}