Physical Review A最新文献

{"title":"Unified treatment of atomic excitation and ionization","authors":"N. W. Antonio, I. Bray, A. S. Kadyrov","doi":"10.1103/physreva.110.032810","DOIUrl":"https://doi.org/10.1103/physreva.110.032810","url":null,"abstract":"A unified treatment of atomic excitation and ionization in ion-atom collisions is proposed. It is demonstrated that the state-resolved excitation cross sections multiplied by <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>n</mi><mn>3</mn></msup></math>, where <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi></math> is the principal quantum number of the excited state, and the corresponding partial singly differential ionization cross section form two parts of a single continuous function. This allows one to obtain the excitation cross section for any state including high-lying Rydberg states and the energy-differential ionization cross section at, and arbitrarily close to, the threshold. The proposed method can be used in any theoretical approaches to excitation and ionization and experimental measurements.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"28 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205864","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":"Error mitigation, optimization, and extrapolation on a trapped-ion testbed","authors":"Oliver G. Maupin, Ashlyn D. Burch, Brandon Ruzic, Christopher G. Yale, Antonio Russo, Daniel S. Lobser, Melissa C. Revelle, Matthew N. Chow, Susan M. Clark, Andrew J. Landahl, Peter J. Love","doi":"10.1103/physreva.110.032416","DOIUrl":"https://doi.org/10.1103/physreva.110.032416","url":null,"abstract":"Current noisy intermediate-scale quantum (NISQ) trapped-ion devices are subject to errors which can significantly impact the accuracy of calculations if left unchecked. A form of error mitigation called zero noise extrapolation (ZNE) can decrease an algorithm's sensitivity to these errors without increasing the number of required qubits. Here we explore different methods for integrating this error mitigation technique into the Variational Quantum Eigensolver (VQE) algorithm for calculating the ground state of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mtext>HeH</mtext><mo>+</mo></msup></math> molecule at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>0.8</mn><mspace width=\"3.33333pt\"></mspace><mtext>Å</mtext></mrow></math> in the presence of experimental noise. Using the Quantum Scientific Computing Open User Testbed (QSCOUT) trapped-ion device, we test three methods of scaling noise for extrapolation: time stretching the two-qubit gates, scaling the sideband detuning parameter, and inserting two-qubit gate identity operations into the ansatz circuit. We find that time stretching and sideband detuning scaling fail to scale the noise on our particular hardware in a way that can be extrapolated to zero noise. Scaling our noise with global gate identity insertions and extrapolating after variational optimization, we achieve error suppression of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>96.8</mn><mo>%</mo></mrow></math>, resulting in an energy estimate within <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>−</mo><mn>0.004</mn><mo>±</mo><mn>0.04</mn></mrow></math> hartree of the ground state energy. This is an improvement, but still outside the chemical accuracy threshold of 0.0016 hartree. Our results show that the efficacy of this error mitigation technique depends on choosing the correct implementation for a given device architecture.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"65 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205869","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":"Quantum thermodynamics of the spin-boson model using the principle of minimal dissipation","authors":"Salvatore Gatto, Alessandra Colla, Heinz-Peter Breuer, Michael Thoss","doi":"10.1103/physreva.110.032210","DOIUrl":"https://doi.org/10.1103/physreva.110.032210","url":null,"abstract":"A recently developed approach to the thermodynamics of open quantum systems, on the basis of the principle of minimal dissipation, is applied to the spin-boson model. Employing a numerically exact quantum dynamical treatment based on the hierarchical equations of motion (HEOM) method, we investigate the influence of the environment on quantities such as work, heat, and entropy production in a range of parameters which go beyond the weak-coupling limit and include both the nonadiabatic and the adiabatic regimes. The results reveal significant differences to the weak-coupling forms of work, heat, and entropy production, which are analyzed in some detail.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"27 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205856","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":"Implementation of controlled-not quantum gate by nonlinear coupled electro-nano-optomechanical oscillators","authors":"Reihaneh Alinaghipour, Hamidreza Mohammadi","doi":"10.1103/physreva.110.032412","DOIUrl":"https://doi.org/10.1103/physreva.110.032412","url":null,"abstract":"A feasibility study is done for the possibility of a universal set of quantum gate implementation based on phononic state via fourth-order Duffing nonlinearity in an optomechanical system. The optomechanical system consists of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>N</mi></mrow></math> doubly clamped coupled nanobeam arrays driven by local static and radio frequency electrical potentials, coupled to a single-mode high-finesse optical cavity. The results show that the ideal <span>cnot</span> gate can be implemented only under nonresonance dynamics when the dissipation processes are negligible.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"65 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205865","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":"Isotope-shift measurement of the 423-nm transition in neutral Ca","authors":"David Röser, Lukas Möller, Hans Keßler, Simon Stellmer","doi":"10.1103/physreva.110.032809","DOIUrl":"https://doi.org/10.1103/physreva.110.032809","url":null,"abstract":"We report on saturated absorption spectroscopy measurements of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mrow><mo>(</mo><mn>4</mn><msup><mi>s</mi><mn>2</mn></msup><mo>)</mo></mrow><mmultiscripts><mi>S</mi><mn>0</mn><none></none><mprescripts></mprescripts><none></none><mn>1</mn></mmultiscripts><mo>→</mo><mrow><mo>(</mo><mn>4</mn><mi>s</mi><mn>4</mn><mi>p</mi><mo>)</mo></mrow><mmultiscripts><mi>P</mi><mn>1</mn><none></none><mprescripts></mprescripts><none></none><mn>1</mn></mmultiscripts></mrow></math> transition for the four most abundant even-mass isotopes in calcium. By referencing the laser locked to an ultralow expansion cavity and carefully investigating systematic errors, isotope shifts are determined with a precision below <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>100</mn><mspace width=\"0.16em\"></mspace><mi mathvariant=\"normal\">k</mi><mi>Hz</mi></mrow></math>, improving previously reported values by a factor of about 3. A King plot analysis, employing literature values of the 729-<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mspace width=\"0.16em\"></mspace><mi mathvariant=\"normal\">n</mi><mi mathvariant=\"normal\">m</mi></mrow></math> transition in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>Ca</mi><mo>+</mo></msup></math> ions, shows excellent linearity. The field and mass shift parameters are determined from King plots with other transitions.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"7 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205866","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":"Toward an optical-fiber-based temporally multiplexed single-photon source","authors":"Agustina G. Magnoni, Laura T. Knoll, Lina Wölcken, Julián Defant, Julián Morales, Miguel A. Larotonda","doi":"10.1103/physreva.110.033712","DOIUrl":"https://doi.org/10.1103/physreva.110.033712","url":null,"abstract":"We demonstrate the feasibility of implementing a photon source with sub-Poissonian emission statistics through temporal multiplexing of a continuous wave heralded photon source in the optical communications wavelength range. We use the time arrival information of a heralding photon to actively modify the delay of the heralded photon in an all-fiber assembly, in order to synchronize the output with respect to an external clock. Within this synchronized operating regime we show that the addition of a single temporal correcting stage can improve the figure of merit for single-photon emission of a heralded photon source. We obtain a brightness improvement factor of approximately 1.8 and an enhancement of the signal-to-noise ratio, quantified by the coincidence-to-accidental counts ratio. These results clear the way for integrated optics nonclassical photon sources in the optical communication band.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"45 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205871","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":"Concatenated Steane code with single-flag syndrome checks","authors":"Balint Pato, Theerapat Tansuwannont, Kenneth R. Brown","doi":"10.1103/physreva.110.032411","DOIUrl":"https://doi.org/10.1103/physreva.110.032411","url":null,"abstract":"A fault-tolerant error correction (FTEC) protocol with a high error suppression rate and low overhead is very desirable for the near-term implementation of quantum computers. In this work, we develop a distance-preserving flag FTEC protocol for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>[</mo><mo>[</mo><mn>49</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>9</mn><mo>]</mo><mo>]</mo></mrow></math> concatenated Steane code, which requires only two ancilla qubits per generator and can be implemented on a planar layout. We generalize the weight-parity error correction (WPEC) technique from Tansuwannont and Leung [<span>Phys. Rev. A</span> <b>104</b>, 042410 (2021)] and find a gate ordering of flag circuits for the concatenated Steane code, which makes syndrome extraction with two ancilla qubits per generator possible. The FTEC protocol is constructed using the optimization tools for flag FTEC developed in Pato <i>et al.</i> [<span>PRX Quantum</span> <b>5</b>, 020336 (2024)] and is simulated under the circuit-level noise model without idling noise. Our simulations give a pseudothreshold of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1.64</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math> for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>[</mo><mo>[</mo><mn>49</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>9</mn><mo>]</mo><mo>]</mo></mrow></math> concatenated Steane code, which is better than a pseudothreshold of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1.43</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math> for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>[</mo><mo>[</mo><mn>61</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>9</mn><mo>]</mo><mo>]</mo></mrow></math> 6.6.6 color code simulated under the same settings. This is in contrast to the code capacity model where the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>[</mo><mo>[</mo><mn>61</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>9</mn><mo>]</mo><mo>]</mo></mrow></math> code performs better.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"45 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205863","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":"Magnomechanically controlled Goos-Hänchen shift in cavity QED","authors":"Muhammad Waseem, Muhammad Irfan, Shahid Qamar","doi":"10.1103/physreva.110.033711","DOIUrl":"https://doi.org/10.1103/physreva.110.033711","url":null,"abstract":"Phenomena involving interactions among magnons, phonons, and photons in cavity magnomechanical systems have attracted considerable attention recently, owing to their potential applications in the microwave frequency range. One such important effect is the response of a probe field to such a tripartite interaction between photon-magnon-phonon. In this paper we study the Goos-Hänchen shift (GHS) of a reflected probe field in a cavity magnomechanical system. We consider a yttrium iron garnet (YIG) sphere positioned within a microwave cavity. A microwave control field directly drives the magnon mode in the YIG sphere, whereas the cavity is driven via a weak probe field. Our results show that the GHS can be coherently controlled through magnon-phonon coupling via the control field. For instance, the GHS can be tuned from positive to negative by tuning the magnon-phonon coupling. Similarly, the effective cavity detuning is another important controlling parameter for the GHS. Furthermore, we observe that the enhancement of the GHS occurs when magnon-phonon coupling is weak at resonance and when the magnon-photon coupling is approximately equal to the loss of microwave photons. Our findings may have potential significance in applications related to microwave switching and sensing.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205868","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":"Modeling beam propagation in a moving nonlinear medium","authors":"Ryan Hogan, Giulia Marcucci, Akbar Safari, A. Nicholas Black, Boris Braverman, Jeremy Upham, Robert W. Boyd","doi":"10.1103/physreva.110.033515","DOIUrl":"https://doi.org/10.1103/physreva.110.033515","url":null,"abstract":"Fully describing light propagation in a rotating, anisotropic medium with thermal nonlinearity requires modeling the interplay between nonlinear refraction, birefringence, and the nonlinear group index. Incorporating these factors into a generalized coupled nonlinear Schrödinger equation and fitting them to recent experimental results reveals two key relationships: the photon drag effect can have a nonlinear component that is dependent on the motion of the medium, and the temporal dynamics of the moving birefringent nonlinear medium create distorted figure-eight-like transverse trajectories at the output. The beam trajectory can be accurately modeled with a full understanding of the propagation effects. Efficiently modeling these effects and accurately predicting the beam's output position has implications for optimizing applications in velocimetry and beam steering. Understanding the roles of competitive nonlinearities gives insight into the creation or suppression of nonlinear phenomena like self-action effects.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"9 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205867","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":"Improving on-demand single-photon-source coherence and indistinguishability through a time-delayed coherent feedback","authors":"Gavin Crowder, Lora Ramunno, Stephen Hughes","doi":"10.1103/physreva.110.l031703","DOIUrl":"https://doi.org/10.1103/physreva.110.l031703","url":null,"abstract":"Single-photon sources (SPSs) are an essential resource for many quantum information technologies. We demonstrate how the inclusion of time-delayed coherent feedback in a scalable waveguide system can significantly improve the two key SPS figures of merit: coherence and indistinguishability. Our feedback protocol is simulated using a quantum trajectory discretized waveguide model which can be used to directly model Hanbury Brown and Twiss (HBT) and Hong-Ou-Mandel (HOM) interferometers. With the proper choice of the round trip phase, the non-Markovian dynamics from the time-delayed feedback improves the indistinguishability of the SPS by up to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>57</mn><mo>%</mo></mrow></math>. We also show how this mechanism suppresses the detrimental effects of off-chip decay and pure dephasing.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"23 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205911","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}