Physical Review X最新文献

{"title":"Scalable Multispecies Ion Transport in a Grid-Based Surface-Electrode Trap","authors":"Robert D. Delaney, Lucas R. Sletten, Matthew J. Cich, Brian Estey, Maya I. Fabrikant, David Hayes, Ian M. Hoffman, James Hostetter, Christopher Langer, Steven A. Moses, Abigail R. Perry, Timothy A. Peterson, Andrew Schaffer, Curtis Volin, Grahame Vittorini, William Cody Burton","doi":"10.1103/physrevx.14.041028","DOIUrl":"https://doi.org/10.1103/physrevx.14.041028","url":null,"abstract":"Quantum processors based on linear arrays of trapped ions have achieved exceptional performance, but scaling to large qubit numbers requires realizing two-dimensional ion arrays as envisioned in the quantum charge-coupled device (QCCD) architecture. Here, we present a scalable method for the control of ion crystals in a grid-based surface-electrode Paul trap and characterize it in the context of transport operations that sort and reorder multispecies crystals. By combining cowiring of control electrodes at translationally symmetric locations in each grid site with the sitewise ability to exchange the voltages applied to two special electrodes gated by a binary input, site-dependent operations can be achieved using only a fixed number of analog voltage signals and a single digital input per site. In two separate experimental systems containing nominally identical grid traps, one using <mjx-container ctxtmenu_counter=\"21\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" overflow=\"linebreak\" role=\"tree\" sre-explorer- style=\"font-size: 100.7%;\" tabindex=\"0\"><mjx-math data-semantic-structure=\"(17 (7 (2 0 1) 3 4 5 6) 8 (16 (11 9 10) 12 13 14 15))\"><mjx-mrow data-semantic-children=\"7,16\" data-semantic-content=\"8\" data-semantic- data-semantic-owns=\"7 8 16\" data-semantic-role=\"subtraction\" data-semantic-speech=\"Superscript 171 Baseline upper Y b Superscript plus minus Superscript 138 Baseline upper B a Superscript plus\" data-semantic-type=\"infixop\"><mjx-mmultiscripts data-semantic-children=\"2,3,4,5,6\" data-semantic-collapsed=\"(7 2 3 4 5 6)\" data-semantic- data-semantic-owns=\"2 3 4 5 6\" data-semantic-parent=\"17\" data-semantic-role=\"unknown\" data-semantic-type=\"tensor\"><mjx-prescripts style=\"vertical-align: 0.555em;\"><mjx-row><mjx-cell><mjx-mrow size=\"s\"><mjx-mn data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"7\" data-semantic-role=\"leftsuper\" data-semantic-type=\"number\"><mjx-c noic=\"true\" style=\"padding-top: 0.639em;\">1</mjx-c><mjx-c noic=\"true\" style=\"padding-top: 0.639em;\">7</mjx-c><mjx-c style=\"padding-top: 0.639em;\">1</mjx-c></mjx-mn></mjx-mrow></mjx-cell></mjx-row><mjx-row style=\"height: 0.796em;\"></mjx-row><mjx-row><mjx-cell><mjx-none data-semantic- data-semantic-parent=\"7\" data-semantic-role=\"leftsub\" data-semantic-type=\"empty\" size=\"s\"></mjx-none></mjx-cell></mjx-row></mjx-prescripts><mjx-mrow><mjx-msup data-semantic-children=\"0,1\" data-semantic- data-semantic-owns=\"0 1\" data-semantic-parent=\"7\" data-semantic-role=\"unknown\" data-semantic-type=\"superscript\"><mjx-mrow><mjx-mi data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"unknown\" data-semantic-type=\"identifier\"><mjx-c noic=\"true\" style=\"padding-top: 0.706em;\">Y</mjx-c><mjx-c style=\"padding-top: 0.706em;\">b</mjx-c></mjx-mi></mjx-mrow><mjx-script style=\"vertical-align: 0.433em;\"><mjx-mrow size=\"s\"><mjx-mo data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"addition\" data-semantic-type=\"operator\"><mjx-c>+</mjx-c></mjx-mo></mjx-mrow></mjx-script></mjx","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"16 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561963","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":"Opening the Black Box inside Grover’s Algorithm","authors":"E. M. Stoudenmire, Xavier Waintal","doi":"10.1103/physrevx.14.041029","DOIUrl":"https://doi.org/10.1103/physrevx.14.041029","url":null,"abstract":"Grover’s algorithm is one of the primary algorithms offered as evidence that quantum computers can provide an advantage over classical computers. It involves an “oracle” (external quantum subroutine), which must be specified for a given application and whose internal structure is not part of the formal scaling of the quadratic quantum speedup guaranteed by the algorithm. Grover’’s algorithm also requires exponentially many calls to the quantum oracle (approximately <mjx-container ctxtmenu_counter=\"41\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" overflow=\"linebreak\" role=\"tree\" sre-explorer- style=\"font-size: 100.7%;\" tabindex=\"0\"><mjx-math data-semantic-structure=\"(3 (2 0 1))\"><mjx-msqrt data-semantic-children=\"2\" data-semantic- data-semantic-owns=\"2\" data-semantic-role=\"unknown\" data-semantic-speech=\"StartRoot 2 Superscript n Baseline EndRoot\" data-semantic-type=\"sqrt\"><mjx-sqrt><mjx-surd><mjx-mo><mjx-c>√</mjx-c></mjx-mo></mjx-surd><mjx-box style=\"padding-top: 0.28em; border-top-width: 0.085em;\"><mjx-msup data-semantic-children=\"0,1\" data-semantic- data-semantic-owns=\"0 1\" data-semantic-parent=\"3\" data-semantic-role=\"integer\" data-semantic-type=\"superscript\"><mjx-mn data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"integer\" data-semantic-type=\"number\"><mjx-c>2</mjx-c></mjx-mn><mjx-script style=\"vertical-align: 0.289em;\"><mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\" size=\"s\"><mjx-c>𝑛</mjx-c></mjx-mi></mjx-script></mjx-msup></mjx-box></mjx-sqrt></mjx-msqrt></mjx-math></mjx-container> calls where n is the number of qubits) to succeed, raising the question of its implementation on both noisy and error-corrected quantum computers. In this work, we construct a quantum-inspired algorithm executable on a classical computer that performs Grover’s task in a linear number of calls to (simulations of) the oracle—an exponentially smaller number than Grover’s algorithm—and demonstrate this algorithm explicitly for Boolean satisfiability problems. The complexity of our algorithm depends on the cost to simulate the oracle once, which may or may not be exponential, depending on its internal structure. Indeed, Grover’s algorithm does not have an <i>a priori</i> quantum speedup as soon as one is given access to the “source code” of the oracle, which may reveal an internal structure of the problem. Our findings illustrate this point explicitly, as our algorithm exploits the structure of the quantum circuit used to program the quantum computer to speed up the search. There are still problems where Grover’s algorithm would provide an asymptotic speedup if it could be run accurately for large enough sizes. Our quantum-inspired algorithm provides lower bounds, in terms of the quantum-circuit complexity, for the quantum hardware to beat classical approaches","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"79 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562239","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":"First Principles Numerical Demonstration of Emergent Decoherent Histories","authors":"Philipp Strasberg, Teresa E. Reinhard, Joseph Schindler","doi":"10.1103/physrevx.14.041027","DOIUrl":"https://doi.org/10.1103/physrevx.14.041027","url":null,"abstract":"Within the histories formalism the decoherence functional is a formal tool to investigate the emergence of classicality in isolated quantum systems, yet an explicit evaluation of it from first principles has not been reported. We provide such an evaluation for up to five-time histories based on exact numerical diagonalization of the Schrödinger equation. We find a robust emergence of decoherence for slow and coarse observables of a generic random matrix model and extract a finite-size scaling law by varying the Hilbert space dimension over 4 orders of magnitude. Specifically, we conjecture and observe an exponential suppression of coherent effects as a function of the particle number of the system. This suggests a solution to the preferred basis problem of the many-worlds interpretation (or the set selection problem of the histories formalism) within a minimal theoretical framework without relying on environmentally induced decoherence, quantum Darwinism, Markov approximations, low-entropy initial states, or ensemble averages.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"7 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555833","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":"Impact of Nuclear Motion on Light-Induced Bimolecular Interaction Dynamics","authors":"Menghang Shi, Hao Huang, Chenxu Lu, Shengzhe Pan, Lianrong Zhou, Zhejun Jiang, Hongcheng Ni, Wenbin Zhang, Jian Wu","doi":"10.1103/physrevx.14.041001","DOIUrl":"https://doi.org/10.1103/physrevx.14.041001","url":null,"abstract":"In chemical reactions, the nuclear motion of the molecules plays a crucial role in determining the reaction rates and outcomes. Employing the cold target recoil ion momentum spectroscopy and femtosecond pump-probe techniques, we perform a molecular-level study into the influence of nuclear vibrations on light-induced bimolecular reactions within <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mi mathvariant=\"normal\">H</mi></mrow><mrow><mn>2</mn></mrow></msub><mtext>−</mtext><msub><mrow><mi mathvariant=\"normal\">D</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math> dimers. The study focuses on the formation dynamics of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">D</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">H</mi><mo>+</mo></msup></mrow></math> and <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">H</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">D</mi><mo>+</mo></msup></mrow></math> cations, shedding light on the interplay between translational and vibrational motions of the nuclei steering the bimolecular reactions. Our observations reveal a notable yield ratio of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><mo>:</mo><mn>1.6</mn></mrow></math> between <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">H</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">D</mi><mo>+</mo></msup></mrow></math> and <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">D</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">H</mi><mo>+</mo></msup></mrow></math> channels, accompanied with a faster formation of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">D</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">H</mi><mo>+</mo></msup></mrow></math> compared to <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi mathvariant=\"normal\">H</mi><mn>2</mn></msub><msup><mi mathvariant=\"normal\">D</mi><mo>+</mo></msup></mrow></math>. Molecular dynamics simulations unveil that the faster vibrational motion of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msubsup><mrow><mi mathvariant=\"normal\">H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></mrow></math> than that of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msubsup><mrow><mi mathvariant=\"normal\">D</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></mrow></math> upon single ionization within the dimer accounts for these differences. Our findings provide new insight into the time-resolved kinetic isotope effect on the bimolecular reactions, highlighting the critical relationship between nuclear vibrational motions and reaction dynamics.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"4 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369013","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":"Quantum Entanglement between Optical and Microwave Photonic Qubits","authors":"Srujan Meesala, David Lake, Steven Wood, Piero Chiappina, Changchun Zhong, Andrew D. Beyer, Matthew D. Shaw, Liang Jiang, Oskar Painter","doi":"10.1103/physrevx.14.031055","DOIUrl":"https://doi.org/10.1103/physrevx.14.031055","url":null,"abstract":"Entanglement is an extraordinary feature of quantum mechanics. Sources of entangled optical photons were essential to test the foundations of quantum physics through violations of Bell’s inequalities. More recently, entangled many-body states have been realized via strong nonlinear interactions in microwave circuits with superconducting qubits. Here, we demonstrate a chip-scale source of entangled optical and microwave photonic qubits. Our device platform integrates a piezo-optomechanical transducer with a superconducting resonator which is robust under optical illumination. We drive a photon-pair generation process and employ a dual-rail encoding intrinsic to our system to prepare entangled states of microwave and optical photons. We place a lower bound on the fidelity of the entangled state by measuring microwave and optical photons in two orthogonal bases. This entanglement source can directly interface telecom wavelength time-bin qubits and gigahertz frequency superconducting qubits, two well-established platforms for quantum communication and computation, respectively.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"4 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369292","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":"Geometric Landscape Annealing as an Optimization Principle Underlying the Coherent Ising Machine","authors":"Atsushi Yamamura, Hideo Mabuchi, Surya Ganguli","doi":"10.1103/physrevx.14.031054","DOIUrl":"https://doi.org/10.1103/physrevx.14.031054","url":null,"abstract":"Given the fundamental importance of combinatorial optimization across many diverse domains, there has been widespread interest in the development of unconventional physical computing architectures that can deliver better solutions with lower resource costs. However, a theoretical understanding of their performance remains elusive. We develop such understanding for the case of the coherent Ising machine (CIM), a network of optical parametric oscillators that can be applied to any quadratic unconstrained binary optimization problem. We focus on how the CIM finds low-energy solutions of the Sherrington-Kirkpatrick spin glass. As the laser gain of this system is annealed, the CIM interpolates between gradient descent on coupled soft spins to descent on coupled binary spins. By combining the Kac-Rice formula, the replica method, and supersymmetry breaking, we develop a detailed understanding of the evolving geometry of the high-dimensional energy landscape of the CIM as the laser gain increases, finding several phase transitions in the landscape, from flat to rough to rigid. Additionally, we develop a novel cavity method that provides a geometric interpretation of supersymmetry breaking in terms of the reactivity of a rough landscape to specific external perturbations. Our energy landscape theory successfully matches numerical experiments, provides geometric insights into the principles of CIM operation, and yields optimal annealing schedules.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"41 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328960","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":"Theory of Stimulated Brillouin Scattering in Fibers for Highly Multimode Excitations","authors":"Kabish Wisal, Stephen C. Warren-Smith, Chun-Wei Chen, Hui Cao, A. Douglas Stone","doi":"10.1103/physrevx.14.031053","DOIUrl":"https://doi.org/10.1103/physrevx.14.031053","url":null,"abstract":"Stimulated Brillouin scattering (SBS) is often an unwanted loss mechanism in both active and passive fibers. Highly multimode excitation of fibers has been proposed as a novel route toward efficient SBS suppression. Here, we develop a detailed, quantitative theory which confirms this proposal and elucidates the physical mechanisms involved. Starting from the vector optical and scalar acoustic equations, we derive appropriate nonlinear coupled mode equations for the signal and Stokes modal amplitudes and an analytical formula for the SBS (Stokes) gain with applicable approximations, such as the neglect of shear effects. This allows us to calculate the exponential growth rate of the Stokes power as a function of the distribution of power in a highly multimode signal. The peak value of the gain spectrum across the excited modes determines the SBS threshold—the maximum SBS-limited power that can be sent through the fiber. The theory shows that the peak SBS gain is greatly reduced by highly multimode excitation due to gain broadening and relatively weaker intermodal SBS gain. The inclusion of exact vector optical modes in the calculation is crucial in order to capture the incomplete intermodal coupling due to mismatch of polarization patterns of higher-order modes. We demonstrate that equal excitation of the 160 modes of a commercially available, highly multimode circular step index fiber raises the SBS threshold by a factor of 6.5 and find comparable suppression of SBS in similar fibers with a <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"sans-serif\">D</mi></mrow></math>-shaped cross section.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"35 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321064","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":"Theoretical Description of Pump-Probe Experiments in Charge-Density-Wave Materials out to Long Times","authors":"Marko D. Petrović, Manuel Weber, James K. Freericks","doi":"10.1103/physrevx.14.031052","DOIUrl":"https://doi.org/10.1103/physrevx.14.031052","url":null,"abstract":"We describe coupled nonequilibrium electron-phonon systems semiclassically—Ehrenfest dynamics for the phonons and quantum mechanics for the electrons—using a classical Monte Carlo approach that determines the nonequilibrium response to a large pump field. The semiclassical approach is expected to be accurate, because the phonons are excited to average energies much higher than the phonon frequency, eliminating the need for a quantum description. The numerical efficiency of this method allows us to perform a self-consistent time evolution out to very long times (tens of picoseconds), enabling us to model pump-probe experiments of a charge-density-wave (CDW) material. Our system is a half-filled, one-dimensional (1D) Holstein chain that exhibits CDW ordering due to a Peierls transition. The chain is subjected to a time-dependent electromagnetic pump field that excites it out of equilibrium, and then a second probe pulse is applied after a time delay. By evolving the system to long times, we capture the complete process of lattice excitation and subsequent relaxation to a new equilibrium, due to an exchange of energy between the electrons and the lattice, leading to lattice relaxation at finite temperatures. We employ an indirect (impulsive) driving mechanism of the lattice by the pump pulse due to the direct driving of the electrons. We identify two driving regimes, where the pump can either cause small perturbations or completely invert the initial CDW order. Our work successfully describes the ringing of the amplitude mode in CDW systems that has long been seen in experiment but never successfully explained by microscopic theory. We also describe the fluence-dependent crossover that inverts the CDW order parameter and changes the phonon dynamics. Finally, we illustrate how this method can examine a number of different types of experiments including photoemission, x-ray diffraction, and two-dimensional (2D) spectroscopy.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"2 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317623","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":"Exploring the Strong Interaction of Three-Body Systems at the LHC","authors":"S. Acharyaet al.(ALICE Collaboration)","doi":"10.1103/physrevx.14.031051","DOIUrl":"https://doi.org/10.1103/physrevx.14.031051","url":null,"abstract":"Deuterons are atomic nuclei composed of a neutron and a proton held together by the strong interaction. Unbound ensembles composed of a deuteron and a third nucleon have been investigated in the past using scattering experiments, and they constitute a fundamental reference in nuclear physics to constrain nuclear interactions and the properties of nuclei. In this work, <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mtext>−</mtext><mi>d</mi></mrow></math> and <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mtext>−</mtext><mi>d</mi></mrow></math> femtoscopic correlations measured by the ALICE Collaboration in proton-proton (<math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi><mi>p</mi></math>) collisions at <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> at the Large Hadron Collider (LHC) are presented. It is demonstrated that correlations in momentum space between deuterons and kaons or protons allow us to study three-hadron systems at distances comparable with the proton radius. The analysis of the <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mtext>−</mtext><mi>d</mi></mrow></math> correlation shows that the relative distances at which deuterons and protons or kaons are produced are around 2 fm. The analysis of the <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mtext>−</mtext><mi>d</mi></mrow></math> correlation shows that only a full three-body calculation that accounts for the internal structure of the deuteron can explain the data. In particular, the sensitivity of the observable to the short-range part of the interaction is demonstrated. These results indicate that correlations involving light nuclei in <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi><mi>p</mi></math> collisions at the LHC will also provide access to any three-body system in the strange and charm sectors.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"77 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313700","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":"Spontaneous Brain Activity Emerges from Pairwise Interactions in the Larval Zebrafish Brain","authors":"Richard E. Rosch, Dominic R. W. Burrows, Christopher W. Lynn, Arian Ashourvan","doi":"10.1103/physrevx.14.031050","DOIUrl":"https://doi.org/10.1103/physrevx.14.031050","url":null,"abstract":"Brain activity is characterized by brainwide spatiotemporal patterns that emerge from synapse-mediated interactions between individual neurons. Calcium imaging provides access to <i>in vivo</i> recordings of whole-brain activity at single-neuron resolution and, therefore, allows the study of how large-scale brain dynamics emerge from local activity. In this study, we use a statistical mechanics approach—the pairwise maximum entropy model—to infer microscopic network features from collective patterns of activity in the larval zebrafish brain and relate these features to the emergence of observed whole-brain dynamics. Our findings indicate that the pairwise interactions between neural populations and their intrinsic activity states are sufficient to explain observed whole-brain dynamics. In fact, the pairwise relationships between neuronal populations estimated with the maximum entropy model strongly correspond to observed structural connectivity patterns. Model simulations also demonstrated how tuning pairwise neuronal interactions drives transitions between observed physiological regimes and pathologically hyperexcitable whole-brain regimes. Finally, we use virtual resection to identify the brain structures that are important for maintaining the brain in a physiological dynamic regime. Together, our results indicate that whole-brain activity emerges from a complex dynamical system that transitions between basins of attraction whose strength and topology depend on the connectivity between brain areas.","PeriodicalId":20161,"journal":{"name":"Physical Review X","volume":"31 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313701","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}