Physical review letters最新文献

{"title":"Fundamental Limit on the Power of Entanglement Assistance in Quantum Communication","authors":"Lasse H. Wolff, Paula Belzig, Matthias Christandl, Bergfinnur Durhuus, Marco Tomamichel","doi":"10.1103/physrevlett.134.020802","DOIUrl":"https://doi.org/10.1103/physrevlett.134.020802","url":null,"abstract":"The optimal rate of reliable communication over a quantum channel can be enhanced by preshared entanglement. Whereas the enhancement may be unbounded in infinite-dimensional settings even when the input power is constrained, a long-standing conjecture asserts that the ratio between the entanglement-assisted and unassisted classical capacities is bounded in finite-dimensional settings [Bennett , ]. In this Letter, we prove this conjecture by showing that their ratio is upper bounded by o</a:mi>(</a:mo>d</a:mi></a:mrow>2</a:mn></a:mrow></a:msup>)</a:mo></a:mrow></a:math>, where <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>d</e:mi></e:math> is the input dimension of the channel. An application to quantum communication with noisy encoders and decoders is given. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"11 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Optical Imaging of Laser-Driven Fast Electron Weibel-like Filamentation in Overcritical Density Plasma","authors":"N. P. Dover, O. Tresca, N. Cook, O. C. Ettlinger, R. J. Kingham, C. Maharjan, M. N. Polyanskiy, P. Shkolnikov, I. Pogorelsky, Z. Najmudin","doi":"10.1103/physrevlett.134.025102","DOIUrl":"https://doi.org/10.1103/physrevlett.134.025102","url":null,"abstract":"We report on the measurement of filamented transport of laser-generated fast electron beams in near-critical density plasma. A relativistic intensity long-wave-infrared laser irradiated a hydrodynamically shaped helium gas flow at an electron density n</a:mi></a:mrow>e</a:mi></a:mrow></a:msub>≃</a:mo>10</a:mn></a:mrow>25</a:mn></a:mrow></a:msup></a:mtext></a:mtext>m</a:mi></a:mrow>−</a:mo>3</a:mn></a:mrow></a:msup></a:mrow></a:math>, generating a large flux of fast electrons that propagated beyond the critical surface. The beam-to-background electron density ratio was sufficiently high to drive growth of Weibel-like filamentation, which was measured by optical probing to extend up to <d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><d:mrow><d:mn>800</d:mn><d:mtext> </d:mtext><d:mtext> </d:mtext><d:mi mathvariant=\"normal\">μ</d:mi><d:mi mathvariant=\"normal\">m</d:mi></d:mrow></d:math> with radii <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><h:mrow><h:mo>∼</h:mo><h:mn>10</h:mn><h:mtext> </h:mtext><h:mtext> </h:mtext><h:mi mathvariant=\"normal\">μ</h:mi><h:mi mathvariant=\"normal\">m</h:mi></h:mrow></h:math>. Particle-in-cell simulations reproduce the main features of the filamentation generation, suggesting that collisionless processes are dominant in these interactions. Expansion of the filaments after formation infers a fast electron heated plasma temperature <l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><l:mo>∼</l:mo><l:mn>400</l:mn><l:mtext> </l:mtext><l:mtext> </l:mtext><l:mi>eV</l:mi></l:math> in the overcritical density plasma. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"24 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Symmetry Breaking in the Superionic Phase of Silver Iodide","authors":"Amir Hajibabaei, William J. Baldwin, Gábor Csányi, Stephen J. Cox","doi":"10.1103/physrevlett.134.026306","DOIUrl":"https://doi.org/10.1103/physrevlett.134.026306","url":null,"abstract":"In the superionic phase of silver iodide, we observe a distorted tetragonal structure characterized by symmetry breaking in the cation distribution. This phase competes with the well known bcc phase with a symmetric cation distribution, at an energetic cost of only a few meV</a:mi>/</a:mo>atom</a:mi></a:mrow></a:math>. The small energy difference suggests that these competing structures may both be thermally accessible near the superionic transition temperature. We also find that the distribution of silver ions depends on the low-temperature parent polymorph, with memory persisting in the superionic phase on the nanosecond timescales accessible in our simulations. Furthermore, simulations on the order of 100 ns reveal that even at temperatures where the bcc phase is stable, significant fluctuations toward the tetragonal lattice structure remain. Our results are consistent with many “anomalous” experimental observations and offer a molecular mechanism for the “memory effect” in silver iodide. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"16 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"In+115−Yb+172 Coulomb Crystal Clock with 2.5×10−18 Systematic Uncertainty","authors":"H. N. Hausser, J. Keller, T. Nordmann, N. M. Bhatt, J. Kiethe, H. Liu, I. M. Richter, M. von Boehn, J. Rahm, S. Weyers, E. Benkler, B. Lipphardt, S. Dörscher, K. Stahl, J. Klose, C. Lisdat, M. Filzinger, N. Huntemann, E. Peik, T. E. Mehlstäubler","doi":"10.1103/physrevlett.134.023201","DOIUrl":"https://doi.org/10.1103/physrevlett.134.023201","url":null,"abstract":"We present a scalable mixed-species Coulomb crystal clock based on the S&lt;/a:mi&gt;&lt;/a:mrow&gt;0&lt;/a:mn&gt;&lt;/a:mrow&gt;&lt;/a:msub&gt;&lt;/a:mrow&gt;1&lt;/a:mn&gt;&lt;/a:mrow&gt;&lt;/a:mmultiscripts&gt;&lt;/a:mrow&gt;↔&lt;/a:mo&gt;P&lt;/a:mi&gt;&lt;/a:mrow&gt;3&lt;/a:mn&gt;&lt;/a:mrow&gt;&lt;/a:mmultiscripts&gt;&lt;/a:mrow&gt;0&lt;/a:mn&gt;&lt;/a:mrow&gt;&lt;/a:msub&gt;&lt;/a:mrow&gt;&lt;/a:math&gt; transition in &lt;d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;d:mrow&gt;&lt;d:mmultiscripts&gt;&lt;d:mrow&gt;&lt;d:msup&gt;&lt;d:mrow&gt;&lt;d:mi&gt;In&lt;/d:mi&gt;&lt;/d:mrow&gt;&lt;d:mrow&gt;&lt;d:mo&gt;+&lt;/d:mo&gt;&lt;/d:mrow&gt;&lt;/d:msup&gt;&lt;/d:mrow&gt;&lt;d:mprescripts/&gt;&lt;d:none/&gt;&lt;d:mrow&gt;&lt;d:mn&gt;115&lt;/d:mn&gt;&lt;/d:mrow&gt;&lt;/d:mmultiscripts&gt;&lt;/d:mrow&gt;&lt;/d:math&gt;. &lt;f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;f:mrow&gt;&lt;f:mmultiscripts&gt;&lt;f:mrow&gt;&lt;f:msup&gt;&lt;f:mrow&gt;&lt;f:mi&gt;Yb&lt;/f:mi&gt;&lt;/f:mrow&gt;&lt;f:mrow&gt;&lt;f:mo&gt;+&lt;/f:mo&gt;&lt;/f:mrow&gt;&lt;/f:msup&gt;&lt;/f:mrow&gt;&lt;f:mprescripts/&gt;&lt;f:none/&gt;&lt;f:mrow&gt;&lt;f:mn&gt;172&lt;/f:mn&gt;&lt;/f:mrow&gt;&lt;/f:mmultiscripts&gt;&lt;/f:mrow&gt;&lt;/f:math&gt; ions are cotrapped and used for sympathetic cooling. Reproducible interrogation conditions for mixed-species Coulomb crystals are ensured by a conditional preparation sequence with permutation control. We demonstrate clock operation with a &lt;h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;h:mrow&gt;&lt;h:mn&gt;1&lt;/h:mn&gt;&lt;h:msup&gt;&lt;h:mrow&gt;&lt;h:mi&gt;In&lt;/h:mi&gt;&lt;/h:mrow&gt;&lt;h:mrow&gt;&lt;h:mo&gt;+&lt;/h:mo&gt;&lt;/h:mrow&gt;&lt;/h:msup&gt;&lt;h:mtext&gt;−&lt;/h:mtext&gt;&lt;h:mn&gt;3&lt;/h:mn&gt;&lt;h:msup&gt;&lt;h:mrow&gt;&lt;h:mi&gt;Yb&lt;/h:mi&gt;&lt;/h:mrow&gt;&lt;h:mrow&gt;&lt;h:mo&gt;+&lt;/h:mo&gt;&lt;/h:mrow&gt;&lt;/h:msup&gt;&lt;/h:mrow&gt;&lt;/h:math&gt; crystal, achieving a relative systematic uncertainty of &lt;j:math xmlns:j=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;j:mn&gt;2.5&lt;/j:mn&gt;&lt;j:mo&gt;×&lt;/j:mo&gt;&lt;j:msup&gt;&lt;j:mn&gt;10&lt;/j:mn&gt;&lt;j:mrow&gt;&lt;j:mo&gt;−&lt;/j:mo&gt;&lt;j:mn&gt;18&lt;/j:mn&gt;&lt;/j:mrow&gt;&lt;/j:msup&gt;&lt;/j:math&gt; and a relative frequency instability of &lt;l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;l:mrow&gt;&lt;l:mn&gt;1.6&lt;/l:mn&gt;&lt;l:mo&gt;×&lt;/l:mo&gt;&lt;l:msup&gt;&lt;l:mrow&gt;&lt;l:mn&gt;10&lt;/l:mn&gt;&lt;/l:mrow&gt;&lt;l:mrow&gt;&lt;l:mo&gt;−&lt;/l:mo&gt;&lt;l:mn&gt;15&lt;/l:mn&gt;&lt;/l:mrow&gt;&lt;/l:msup&gt;&lt;l:mo&gt;/&lt;/l:mo&gt;&lt;l:msqrt&gt;&lt;l:mrow&gt;&lt;l:mi&gt;τ&lt;/l:mi&gt;&lt;l:mo&gt;/&lt;/l:mo&gt;&lt;l:mn&gt;1&lt;/l:mn&gt;&lt;l:mtext&gt; &lt;/l:mtext&gt;&lt;l:mtext&gt; &lt;/l:mtext&gt;&lt;l:mi mathvariant=\"normal\"&gt;s&lt;/l:mi&gt;&lt;/l:mrow&gt;&lt;/l:msqrt&gt;&lt;/l:mrow&gt;&lt;/l:math&gt;. We report on absolute frequency measurements with an uncertainty of &lt;o:math xmlns:o=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;o:mn&gt;1.3&lt;/o:mn&gt;&lt;o:mo&gt;×&lt;/o:mo&gt;&lt;o:msup&gt;&lt;o:mn&gt;10&lt;/o:mn&gt;&lt;o:mrow&gt;&lt;o:mo&gt;−&lt;/o:mo&gt;&lt;o:mn&gt;16&lt;/o:mn&gt;&lt;/o:mrow&gt;&lt;/o:msup&gt;&lt;/o:math&gt; and optical frequency comparisons with clocks based on &lt;q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;q:mrow&gt;&lt;q:mmultiscripts&gt;&lt;q:mrow&gt;&lt;q:msup&gt;&lt;q:mrow&gt;&lt;q:mi&gt;Yb&lt;/q:mi&gt;&lt;/q:mrow&gt;&lt;q:mrow&gt;&lt;q:mo&gt;+&lt;/q:mo&gt;&lt;/q:mrow&gt;&lt;/q:msup&gt;&lt;/q:mrow&gt;&lt;q:mprescripts/&gt;&lt;q:none/&gt;&lt;q:mrow&gt;&lt;q:mn&gt;171&lt;/q:mn&gt;&lt;/q:mrow&gt;&lt;/q:mmultiscripts&gt;&lt;/q:mrow&gt;&lt;/q:math&gt; (&lt;s:math xmlns:s=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;s:mi&gt;E&lt;/s:mi&gt;&lt;s:mn&gt;3&lt;/s:mn&gt;&lt;/s:math&gt;) and &lt;u:math xmlns:u=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;u:mrow&gt;&lt;u:mmultiscripts&gt;&lt;u:mrow&gt;&lt;u:mi&gt;Sr&lt;/u:mi&gt;&lt;/u:mrow&gt;&lt;u:mprescripts/&gt;&lt;u:none/&gt;&lt;u:mrow&gt;&lt;u:mn&gt;87&lt;/u:mn&gt;&lt;/u:mrow&gt;&lt;/u:mmultiscrip","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"30 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Non-Markovian Feedback for Optimized Quantum Error Correction","authors":"Matteo Puviani, Sangkha Borah, Remmy Zen, Jan Olle, Florian Marquardt","doi":"10.1103/physrevlett.134.020601","DOIUrl":"https://doi.org/10.1103/physrevlett.134.020601","url":null,"abstract":"Bosonic codes allow the encoding of a logical qubit in a single component device, utilizing the infinitely large Hilbert space of a harmonic oscillator. In particular, the Gottesman-Kitaev-Preskill code has recently been demonstrated to be correctable well beyond the break-even point of the best passive encoding in the same system. Current approaches to quantum error correction (QEC) for this system are based on protocols that use feedback, but the response is based only on the latest measurement outcome. In our work, we use the recently proposed feedback-GRAPE (gradient-ascent pulse engineering with feedback) method to train a recurrent neural network that provides a QEC scheme based on memory, responding in a non-Markovian way to the full history of previous measurement outcomes, optimizing all subsequent unitary operations. This approach significantly outperforms current strategies and paves the way for more powerful measurement-based QEC protocols. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"30 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Coherence of an Electronic Two-Level System under Continuous Charge Sensing by a Quantum Dot Detector","authors":"Subhomoy Haldar, Morten Munk, Harald Havir, Waqar Khan, Sebastian Lehmann, Claes Thelander, Kimberly A. Dick, Peter Samuelsson, Patrick P. Potts, Ville F. Maisi","doi":"10.1103/physrevlett.134.023601","DOIUrl":"https://doi.org/10.1103/physrevlett.134.023601","url":null,"abstract":"We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge state of the two-level system is monitored by a capacitively coupled single quantum dot detector that imposes a backaction effect on the system. The measured backaction is well described by an additional decoherence rate, approximately linearly proportional to the detector electron tunneling rate. We provide a model for the decoherence rate arising due to level detuning fluctuations induced by detector charge fluctuations. The theory predicts a factor of 2 lower decoherence rates than observed in the experiment, suggesting the need for a more elaborate theory accounting for additional sources of decoherence. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Distinguishing Dirac from Majorana Heavy Neutrino at Future Lepton Colliders","authors":"Qing-Hong Cao, Kun Cheng, Yandong Liu","doi":"10.1103/physrevlett.134.021801","DOIUrl":"https://doi.org/10.1103/physrevlett.134.021801","url":null,"abstract":"We propose to identify whether a sterile neutrino is Dirac-type or Majorana-type by counting the peak of the rapidity distribution at lepton colliders. Our method requires only one charged-lepton tagging, and the nature of sterile neutrinos can be pinned down once they are confirmed. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"31 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Quantized Axial Charge of Staggered Fermions and the Chiral Anomaly","authors":"Arkya Chatterjee, Salvatore D. Pace, Shu-Heng Shao","doi":"10.1103/physrevlett.134.021601","DOIUrl":"https://doi.org/10.1103/physrevlett.134.021601","url":null,"abstract":"In the 1</a:mn>+</a:mo>1</a:mn>D</a:mi></a:mrow></a:math> ultralocal lattice Hamiltonian for staggered fermions with a finite-dimensional Hilbert space, there are two conserved, integer-valued charges that flow in the continuum limit to the vector and axial charges of a massless Dirac fermion with a perturbative anomaly. Each of the two lattice charges generates an ordinary U(1) global symmetry that acts locally on operators and can be gauged individually. Interestingly, they do not commute on a finite lattice and generate the Onsager algebra, but their commutator goes to zero in the continuum limit. The chiral anomaly is matched by this non-Abelian algebra, which is consistent with the Nielsen-Ninomiya theorem. We further prove that the presence of these two conserved lattice charges forces the low-energy phase to be gapless, reminiscent of the consequence from perturbative anomalies of continuous global symmetries in continuum field theory. Upon bosonization, these two charges lead to two exact U(1) symmetries in the XX model that flow to the momentum and winding symmetries in the free boson conformal field theory. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"4 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Beyond the Quantum Cramér-Rao Bound","authors":"J. R. Hervas, A. Z. Goldberg, A. S. Sanz, Z. Hradil, J. Řeháček, L. L. Sánchez-Soto","doi":"10.1103/physrevlett.134.010804","DOIUrl":"https://doi.org/10.1103/physrevlett.134.010804","url":null,"abstract":"The quantum Cramér-Rao bound (QCRB) stands as a cornerstone of quantum metrology. Yet, akin to its classical counterpart, it provides only local information and overlooks higher-order details. We leverage the theory of higher-order asymptotics to circumvent these issues, providing corrections to the performance of estimators beyond the QCRB. While the QCRB often yields a whole family of optimal states and several optimal measurements, our approach allows us to identify optimal states and measurements within the family that are otherwise equivalent according to the QCRB alone; these are requisite for optimal metrology before reaching the asymptotic limit. These results are especially pertinent when dealing with unitary processes. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"5 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"High-Temperature QCD Static Potential beyond Leading Order","authors":"Margaret E. Carrington, Cristina Manuel, Joan Soto","doi":"10.1103/physrevlett.134.011905","DOIUrl":"https://doi.org/10.1103/physrevlett.134.011905","url":null,"abstract":"We calculate the leading and next-to-leading corrections to the real-time QCD static potential in a high-temperature medium in the region where bound states transit from narrow resonances to wide ones. We find sizable contributions to both the real and the imaginary part of the potential. The calculation involves both loop diagrams calculated in the hard thermal loop effective theory and power corrections to the hard thermal loop Lagrangian calculated in QCD. We compare our results with recent lattice data and check the consistency of different methods used in lattice calculations. We also discuss the usefulness of our results to guide lattice inputs. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"28 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}