Reports on progress in physics. Physical Society (Great Britain)最新文献

{"title":"Continuous and deterministic all-photonic cluster state of indistinguishable photons.","authors":"Zu-En Su, Boaz Taitler, Ido Schwartz, Dan Cogan, Ismail Nassar, Oded Kenneth, Netanel H Lindner, David Gershoni","doi":"10.1088/1361-6633/ad4c93","DOIUrl":"https://doi.org/10.1088/1361-6633/ad4c93","url":null,"abstract":"<p><p>Cluster states are key resources for measurement-based quantum information processing. Photonic cluster and graph states, in particular, play indispensable roles in quantum network and quantum metrology. We demonstrate a semiconductor quantum dot based device in which the confined hole spin acts as a needle in a quantum knitting machine producing continuously and deterministically at sub-Gigahertz repetition rate single indistinguishable photons which are all polarization entangled to each other and to the spin in a one dimensional cluster state. By projecting two nonadjacent photons onto circular polarization bases we disentangle the spin from the photons emitted in between. This way we demonstrate a novel way for producing deterministic and continuous all-photonic cluster states. We use polarization tomography on four sequentially detected photons to demonstrate and to directly quantify the robustness of the cluster's entanglement and the determinism in its photon generation.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141494541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative regulation of electron-phonon coupling.","authors":"Shenghai Pei, Zejuan Zhang, Chenyin Jiao, Zhenyu Wang, Jian Lv, Yujun Zhang, Mingyuan Huang, Yanchao Wang, Zenghui Wang, Juan Xia","doi":"10.1088/1361-6633/ad4fbd","DOIUrl":"10.1088/1361-6633/ad4fbd","url":null,"abstract":"<p><p>Electron-phonon (e-p) coupling plays a crucial role in various physical phenomena, and regulation of e-p coupling is vital for the exploration and design of high-performance materials. However, the current research on this topic lacks accurate quantification, hindering further understanding of the underlying physical processes and its applications. In this work, we demonstrate quantitative regulation of e-p coupling, by pressure engineering and<i>in-situ</i>spectroscopy. We successfully observe both a distinct vibrational mode and a strong Stokes shift in layered CrBr₃, which are clear signatures of e-p coupling. This allows us to achieve precise quantification of the Huang-Rhys factor<i>S</i>at the actual sample temperature, thus accurately determining the e-p coupling strength. We further reveal that pressure efficiently regulates the e-p coupling in CrBr₃, evidenced by a remarkable 40% increase in<i>S</i>value. Our results offer an approach for quantifying and modulating e-p coupling, which can be leveraged for exploring and designing functional materials with targeted e-p coupling strengths.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141494543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Homotopy, symmetry, and non-Hermitian band topology.","authors":"Kang Yang, Zhi Li, J Lukas K König, Lukas Rødland, Marcus Stålhammar, Emil J Bergholtz","doi":"10.1088/1361-6633/ad4e64","DOIUrl":"https://doi.org/10.1088/1361-6633/ad4e64","url":null,"abstract":"<p><p>Non-Hermitian matrices are ubiquitous in the description of nature ranging from classical dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering of waves and open quantum many-body systems. Seminal line-gap and point-gap classifications of non-Hermitian systems using K-theory have deepened the understanding of many physical phenomena. However, ample systems remain beyond this description; reference points and lines do not in general distinguish whether multiple non-Hermitian bands exhibit intriguing exceptional points, spectral braids and crossings. To address this we consider two different notions: non-Hermitian band gaps and separation gaps that crucially encompass a broad class of multi-band scenarios, enabling the description of generic band structures with symmetries. With these concepts, we provide a unified and comprehensive classification of both gapped and nodal systems in the presence of physically relevant parity-time (PT) and pseudo-Hermitian symmetries using homotopy theory. This uncovers new stable topology stemming from both eigenvalues and wave functions, and remarkably also implies distinct fragile topological phases. In particular, we reveal different Abelian and non-Abelian phases inPT-symmetric systems, described by frame and braid topology. The corresponding invariants are robust to symmetry-preserving perturbations that do not induce (exceptional) degeneracy, and they also predict the deformation rules of nodal phases. We further demonstrate that spontaneousPTsymmetry breaking is captured by Chern-Euler and Chern-Stiefel-Whitney descriptions, a fingerprint of unprecedented non-Hermitian topology previously overlooked. These results open the door for theoretical and experimental exploration of a rich variety of novel topological phenomena in a wide range of physical platforms.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141494542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Test of lepton flavor universality inB±→K±μ+μ-andB±→K±e+e-decays in proton-proton collisions ats=13TeV.","authors":"The Cms Collaboration","doi":"10.1088/1361-6633/ad4e65","DOIUrl":"10.1088/1361-6633/ad4e65","url":null,"abstract":"<p><p>A test of lepton flavor universality inB±→K±μ+μ-andB±→K±e+e-decays, as well as a measurement of differential and integrated branching fractions of a nonresonantB±→K±μ+μ-decay are presented. The analysis is made possible by a dedicated data set of proton-proton collisions ats=13TeVrecorded in 2018, by the CMS experiment at the LHC, using a special high-rate data stream designed for collecting about 10 billion unbiased b hadron decays. The ratio of the branching fractionsB(B±→K±μ+μ-)toB(B±→K±e+e-)is determined from the measured double ratioR(K)of these decays to the respective branching fractions of theB±→J/ψK±withJ/ψ→μ+μ-ande+e-decays, which allow for significant cancellation of systematic uncertainties. The ratioR(K)is measured in the range1.1<q2<6.0GeV2, where<i>q</i>is the invariant mass of the lepton pair, and is found to beR(K)=0.78-0.23+0.47, in agreement with the standard model expectationR(K)≈1. This measurement is limited by the statistical precision of the electron channel. The integrated branching fraction in the same<i>q</i>²range,B(B±→K±μ+μ-)=(12.42±0.68)×10-8, is consistent with the present world-average value and has a comparable precision.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141494556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of anisotropy in understanding the molecular grounds for density scaling in dynamics of glass-forming liquids.","authors":"A Grzybowski, K Koperwas, M Paluch","doi":"10.1088/1361-6633/ad569d","DOIUrl":"10.1088/1361-6633/ad569d","url":null,"abstract":"<p><p>Molecular Dynamics (MD) simulations of glass-forming liquids play a pivotal role in uncovering the molecular nature of the liquid vitrification process. In particular, much focus was given to elucidating the interplay between the character of intermolecular potential and molecular dynamics behaviour. This has been tried to achieve by simulating the spherical particles interacting via isotropic potential. However, when simulation and experimental data are analysed in the same way by using the density scaling approaches, serious inconsistency is revealed between them. Similar scaling exponent values are determined by analysing the relaxation times and pVT data obtained from computer simulations. In contrast, these values differ significantly when the same analysis is carried out in the case of experimental data. As discussed thoroughly herein, the coherence between results of simulation and experiment can be achieved if anisotropy of intermolecular interactions is introduced to MD simulations. In practice, it has been realized in two different ways: (1) by using the anisotropic potential of the Gay-Berne type or (2) by replacing the spherical particles with quasi-real polyatomic anisotropic molecules interacting through isotropic Lenard-Jones potential. In particular, the last strategy has the potential to be used to explore the relationship between molecular architecture and molecular dynamics behaviour. Finally, we hope that the results presented in this review will also encourage others to explore how 'anisotropy' affects remaining aspects related to liquid-glass transition, like heterogeneity, glass transition temperature, glass forming ability, etc.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141307595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anomalous thermodynamic cost of clock synchronization.","authors":"Cheng Yang, Jiteng Sheng, Haibin Wu","doi":"10.1088/1361-6633/ad5867","DOIUrl":"10.1088/1361-6633/ad5867","url":null,"abstract":"<p><p>Clock synchronization is critically important in positioning, navigation and timing systems. While its performance has been intensively studied in a wide range of disciplines, much less is known for the fundamental thermodynamics of clock synchronization‒what limits the precision and how to optimize the energy cost for clock synchronization. Here, we report the first experimental investigation of two stochastic autonomous clocks synchronization, unveiling the thermodynamic relation between the entropy cost and clock synchronization in an open cavity optomechanical system. Two interacting clocks are synchronized spontaneously owing to the disparate decay rates of hybrid modes by engineering the controllable cavity-mediated dissipative coupling. The measured dependence of the degree of synchronization on the overall entropy cost exhibits an unexpected non-monotonic characteristic, while the relation between the degree of synchronization and the entropy cost for the synchronization is monotonically decreasing. The investigation of transient dynamics of clock synchronization exposes a trade-off between energy and time consumption. Our results demonstrate the possibility of clock synchronization in an effective linear system, reveal the fundamental relation between clock synchronization and thermodynamics, and have a great potential for precision measurements, distributed quantum networks, and biological science.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141322148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum: The measurement of surface gravity (2013<i>Rep. Prog. Phys.</i>76 046101).","authors":"David Crossley, Jacques Hinderer, Umberto Riccardi","doi":"10.1088/1361-6633/ad573b","DOIUrl":"https://doi.org/10.1088/1361-6633/ad573b","url":null,"abstract":"","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141443899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A statistical primer on classical period-finding techniques in astronomy.","authors":"Naomi Giertych, Ahmed Shaban, Pragya Haravu, Jonathan P Williams","doi":"10.1088/1361-6633/ad4586","DOIUrl":"https://doi.org/10.1088/1361-6633/ad4586","url":null,"abstract":"<p><p>The aim of our paper is to investigate the properties of the classical phase-dispersion minimization (PDM), analysis of variance (AOV), string-length (SL), and Lomb-Scargle (LS) power statistics from a statistician's perspective. We confirm that when the data are perturbations of a constant function, i.e. under the null hypothesis of no period in the data, a scaled version of the PDM statistic follows a beta distribution, the AOV statistic follows an F distribution, and the LS power follows a chi-squared distribution with two degrees of freedom. However, the SL statistic does not have a closed-form distribution. We further verify these theoretical distributions through simulations and demonstrate that the extreme values of these statistics (over a range of trial periods), often used for period estimation and determination of the false alarm probability (FAP), follow different distributions than those derived for a single period. We emphasize that multiple-testing considerations are needed to correctly derive FAP bounds. Though, in fact, multiple-testing controls are built into the FAP bound for these extreme-value statistics, e.g. the FAP bound derived specifically for the maximum LS power statistic over a range of trial periods. Additionally, we find that all of these methods are robust to heteroscedastic noise aimed to mimic the degradation or miscalibration of an instrument over time. Finally, we examine the ability of these statistics to detect a non-constant periodic function via simulating data that mimics a well-detached binary system, and we find that the AOV statistic has the most power to detect the correct period, which agrees with what has been observed in practice.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141428421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pioneering research has a new home in a trusted place.","authors":"David Gevaux","doi":"10.1088/1361-6633/ad543a","DOIUrl":"10.1088/1361-6633/ad543a","url":null,"abstract":"<p><p>After 90 years of publishing authoritative reviews, Reports on Progress in Physics is today publishing its first primary research papers. The beginning, we hope, of the journal's evolution into a showcase of the most impactful, ground-breaking and just fascinating physical-science research; a journal that builds trust through rigorous peer review and gives back to the communities we serve. Investing 100% of our funds back into science, we are committed to achieving all of this on a not-for-profit basis that puts science and scientists first.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141428424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Divergence beneath the Brillouin sphere and the phenomenology of prediction error in spherical harmonic series approximations of the gravitational field.","authors":"M Bevis, C Ogle, O Costin, C Jekeli, R D Costin, J Guo, J Fowler, G V Dunne, C K Shum, K Snow","doi":"10.1088/1361-6633/ad44d5","DOIUrl":"10.1088/1361-6633/ad44d5","url":null,"abstract":"<p><p>The Brillouin sphere is defined as the smallest sphere, centered at the origin of the geocentric coordinate system, that incorporates all the condensed matter composing the planet. The Brillouin sphere touches the Earth at a single point, and the radial line that begins at the origin and passes through that point is called the singular radial line. For about 60 years there has been a persistent anxiety about whether or not a spherical harmonic (SH) expansion of the external gravitational potential,<i>V</i>, will converge beneath the Brillouin sphere. Recently, it was proven that the probability of such convergence is zero. One of these proofs provided an asymptotic relation, called Costin's formula, for the upper bound,<i>E_N</i>, on the absolute value of the prediction error,<i>e_N</i>, of a SH series model,VN(θ,λ,r), truncated at some maximum degree,N=nmax. When the SH series is restricted to (or projected onto) a particular radial line, it reduces to a Taylor series (TS) in1/r. Costin's formula isEN≃BN-b(R/r)N, where<i>R</i>is the radius of the Brillouin sphere. This formula depends on two positive parameters:<i>b</i>, which controls the decay of error amplitude as a function of<i>N</i>when<i>r</i>is fixed, and a scale factor<i>B</i>. We show here that Costin's formula derives from a similar asymptotic relation for the upper bound,<i>A_n</i>on the absolute value of the TS coefficients,<i>a_n</i>, for the same radial line. This formula,An≃Kn-k, depends on degree,<i>n</i>, and two positive parameters,<i>k</i>and<i>K</i>, that are analogous to<i>b</i>and<i>B</i>. We use synthetic planets, for which we can compute the potential,<i>V</i>, and also the radial component of gravitational acceleration,gr=∂V/∂r, to hundreds of significant digits, to validate both of these asymptotic formulas. Let superscript<i>V</i>refer to asymptotic parameters associated with the coefficients and prediction errors for gravitational potential, and superscript<i>g</i>to the coefficients and predictions errors associated with<i>g_r</i>. For polyhedral planets of uniform density we show thatbV=kV=7/2andbg=kg=5/2almost everywhere. We show that the frequency of oscillation (around zero) of the TS coefficients and the series prediction errors, for a given radial line, is controlled by the geocentric angle,<i>α</i>, between that radial line and the singular radial line. We also derive useful identities connectingKV,BV,Kg, and<i>B^g</i>. These identities are expressed in terms of quotients of the various scale factors. The only other quantities involved in these identities are<i>α</i>and<i>R</i>. The phenomenology of 'series divergence' and prediction error (when<i>r</i> < <i>R</i>) can be described as a function of the truncation degree,<i>N</i>, or the depth,<i>d</i>, beneath the Brillouin sphere. For a fixedr⩽R, as<i>N</i>increases from very low values, the upper error bound<i>E_N</i>shrinks until i","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":"87 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141428422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}