Physical review letters最新文献

{"title":"Reconfigurable Self-Phase Modulation Enabled by Cascaded Nonlinear Backaction in Integrated Photonics.","authors":"Chaohan Cui, Liang Zhang, Linran Fan","doi":"10.1103/PhysRevLett.134.103803","DOIUrl":"https://doi.org/10.1103/PhysRevLett.134.103803","url":null,"abstract":"<p><p>Self-phase modulation is ubiquitous in optical systems: It provides foundational functionality to numerous photonic technologies, such as soliton generation and ultrafast pulse compression. However, it remains challenging to directly modify the coefficient of self-phase modulation, which is typically regarded as a fixed property of optical materials and structures. In this work, we overcome this limitation and demonstrate reconfigurable self-phase modulation with an integrated photonic cavity. This is achieved by introducing the engineered backaction from the reservoir photonic resonance through the cascaded second-order nonlinear coupling. The coefficient of self-phase modulation is tuned from -2.7 to +4.7 of its intrinsic value. With negative coefficients, we observe the anomalous self-phase modulation, where photonic resonances are shifted towards higher frequencies. With the reconfigurable self-phase modulation, we further demonstrate the control of spontaneous chiral symmetry breaking in the integrated photonic ring cavity.</p>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"134 10","pages":"103803"},"PeriodicalIF":8.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736056","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":"Giant Gate-Controlled Odd-Parity Magnetoresistance in Magnetized Bilayer Graphene at Room Temperature.","authors":"Divya Sahani, Sunit Das, Kenji Watanabe, Takashi Taniguchi, Amit Agarwal, Aveek Bid","doi":"10.1103/PhysRevLett.134.106301","DOIUrl":"https://doi.org/10.1103/PhysRevLett.134.106301","url":null,"abstract":"<p><p>In this Letter, we report the discovery of giant room-temperature odd-parity magnetoresistance (OMR) in a bilayer graphene heterostructure interfaced with Cr_{2}Ge_{2}Te_{6} (CGT). We show that the OMR is electrostatic gate-voltage tunable, exhibiting maximum value near the graphene band edges and diminishing rapidly with increasing charge carrier density. Our theoretical analysis reveals that the OMR originates from the coupling of out-of-plane components of Berry curvature and orbital magnetic moment with the applied magnetic field, signaling intrinsic time-reversal symmetry breaking in the system. This time-reversal symmetry breaking persists at room temperature within the CGT and bilayer graphene heterostructure despite the bulk CGT exhibiting ferromagnetic transition at 65 K. Our Letter opens new avenues for probing band geometric phenomena through magnetotransport measurements, especially in quantum materials where the anomalous Hall effects are immeasurably small due to the extrinsic scattering-dependent contributions canceling Berry curvature contributions.</p>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"134 10","pages":"106301"},"PeriodicalIF":8.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735990","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":"Stochastic Dark Matter from Curvature Perturbations","authors":"Raghuveer Garani, Michele Redi, Andrea Tesi","doi":"10.1103/physrevlett.134.101005","DOIUrl":"https://doi.org/10.1103/physrevlett.134.101005","url":null,"abstract":"We investigate the production of dark matter from metric perturbations produced during inflation or in standard cosmology. Perturbations break Weyl flatness of the Friedmann-Lemaître-Robertson-Walker metric, allowing conformally coupled fields—in particular, fermions studied here—to be produced even when their mass is negligible. Particle production can be computed by studying the Bogoliubov transformation induced by the stochastic background. For perturbations generated during inflation, we present a closed formula for the resulting abundance of particles that depends solely on the power spectrum of curvature perturbations at the end of inflation. This production mechanism can be dominant especially if the amplitude of curvature perturbations is enhanced for modes that exit the horizon toward the end of inflation. In the simplest scenario, the critical dark matter abundance is reproduced for M</a:mi>≳</a:mo>10</a:mn>6</a:mn></a:msup></a:mtext></a:mtext>GeV</a:mi></a:math>. <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":"33 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618758","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":"Primordial Neutrinos and New Physics: Novel Approach to Solving the Neutrino Boltzmann Equation","authors":"Maksym Ovchynnikov, Vsevolod Syvolap","doi":"10.1103/physrevlett.134.101003","DOIUrl":"https://doi.org/10.1103/physrevlett.134.101003","url":null,"abstract":"Understanding how new physics influences the dynamics of cosmic neutrinos during their decoupling is crucial in light of upcoming precise cosmological observations and the need to reconcile cosmological and laboratory probes. Existing approaches to solving the neutrino Boltzmann equation are often model dependent, computationally inefficient, and yield contradictory results. To solve this problem, we introduce a novel method to comprehensively study neutrino dynamics. We apply this method to several case studies, resolving the discrepancy in the literature about the impact of nonthermal neutrinos on N</a:mi></a:mrow>eff</a:mi></a:mrow></a:msub></a:mrow></a:math> and providing important insights about the role of decaying new physics particles on MeV 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":"92 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608363","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":"Fermiology and Band Structure of Oxygen-Terminated Ti3C2Tx MXene","authors":"Martin Magnuson, Per Eklund, Craig Polley","doi":"10.1103/physrevlett.134.106201","DOIUrl":"https://doi.org/10.1103/physrevlett.134.106201","url":null,"abstract":"The class of two-dimensional carbides and nitrides known as MXenes exhibit remarkable electronic properties. Tailoring these properties, however, requires an in-depth understanding of the band structure and Fermi-surface topology. Surface oxidation of MXenes has previously hampered the characterization of their Fermi surface, which is crucial for understanding the topology and anisotropy in the electronic structure and, ultimately, for tailoring electronic properties. Here, we reveal the Fermi surface topology and band structure of purely oxygen-terminated Ti</a:mi></a:mrow>3</a:mn></a:mrow></a:msub>C</a:mi></a:mrow>2</a:mn></a:mrow></a:msub>T</a:mi></a:mrow>x</a:mi></a:mrow></a:msub></a:mrow></a:math> MXene achieved through rigorous thin film sample preparation and ultrahigh vacuum annealing. Polarized synchrotron radiation-based angle-resolved photoemission spectroscopy reveals electron pockets, bulk band gaps, and a Dirac-like feature in the anisotropic electronic band structure. This paves the way for a fundamental understanding of band engineering of electronic transport properties, providing insights of importance for energy storage devices, transparent conductors, and catalysis. <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":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598983","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":"Black Hole Singularity Resolution in Unimodular Gravity from Unitarity","authors":"Steffen Gielen, Lucía Menéndez-Pidal","doi":"10.1103/physrevlett.134.101501","DOIUrl":"https://doi.org/10.1103/physrevlett.134.101501","url":null,"abstract":"We study the quantum dynamics of an interior planar anti–de Sitter black hole, requiring unitarity in the natural time coordinate conjugate to the cosmological “constant of motion” appearing in unimodular gravity. Both the classical singularity and the horizon are replaced by a nonsingular highly quantum region; semiclassical notions of spacetime evolution are only valid in an intermediate region. For the singularity, our results should be applicable to general black holes: unitarity in unimodular time always implies singularity resolution. <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":"68 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598985","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":"T Duality and TT¯ -like Deformations of Sigma Models","authors":"Daniele Bielli, Christian Ferko, Liam Smith, Gabriele Tartaglino-Mazzucchelli","doi":"10.1103/physrevlett.134.101601","DOIUrl":"https://doi.org/10.1103/physrevlett.134.101601","url":null,"abstract":"We initiate the study of the interplay between T duality and classical stress tensor deformations in two-dimensional sigma models. We first show that a general Abelian T duality commutes with the T</a:mi>T</a:mi>¯</a:mo></a:mover></a:math> deformation, which can be engineered by a gravitational dressing. Then, by using an auxiliary field formulation of stress tensor deformations of the principal chiral model (PCM), we prove that non-Abelian T duality and arbitrary <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>T</e:mi><e:mover accent=\"true\"><e:mi>T</e:mi><e:mo stretchy=\"false\">¯</e:mo></e:mover></e:math>-like flows also commute for theories in this class. We argue that all such auxiliary field deformations of both the PCM and its T dual are classically integrable. <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":"70 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598987","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":"Zero-Energy Photoelectric Effect","authors":"Sajad Azizi, Ulf Saalmann, Jan M. Rost","doi":"10.1103/physrevlett.134.103201","DOIUrl":"https://doi.org/10.1103/physrevlett.134.103201","url":null,"abstract":"We predict a near-threshold (“zero energy”) peak in multiphoton ionization for a dynamical regime where the photon frequency is large compared to the binding energy of the electron. The peak position does not depend on the laser frequency but on the binding energy and the pulse duration. The effect originates from the fact that bound-continuum dipole transitions are stronger than continuum-continuum ones. To clearly observe this zero-energy photoelectric effect, the spectral width of the laser pulse should be comparable to the binding energy of the ionized orbital, and the second ionization potential should be larger than the photon energy. This suggests negative ions as ideal candidates for corresponding experiments. <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":"38 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598982","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":"Unifying Theory of Scaling in Drop Impact: Forces and Maximum Spreading Diameter","authors":"Vatsal Sanjay, Detlef Lohse","doi":"10.1103/physrevlett.134.104003","DOIUrl":"https://doi.org/10.1103/physrevlett.134.104003","url":null,"abstract":"The dynamics of drop impact on a rigid surface strongly depends on the droplet’s velocity, its size, and its material properties. The main characteristics are the droplet’s force exerted on the surface and its maximal spreading radius. The crucial question is how do they depend on the (dimensionless) control parameters, which are the Weber number W</a:mi>e</a:mi></a:mrow></a:math> (nondimensionalized kinetic energy) and the Ohnesorge number <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mi>O</c:mi><c:mi>h</c:mi></c:mrow></c:math> (dimensionless viscosity). Here, we perform direct numerical simulations over the huge parameter range <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mn>1</e:mn><e:mo>≤</e:mo><e:mi>W</e:mi><e:mi>e</e:mi><e:mo>≤</e:mo><e:msup><e:mrow><e:mn>10</e:mn></e:mrow><e:mrow><e:mn>3</e:mn></e:mrow></e:msup></e:mrow></e:math> and <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mrow><g:msup><g:mrow><g:mn>10</g:mn></g:mrow><g:mrow><g:mo>−</g:mo><g:mn>3</g:mn></g:mrow></g:msup><g:mo>≤</g:mo><g:mi>O</g:mi><g:mi>h</g:mi><g:mo>≤</g:mo><g:msup><g:mrow><g:mn>10</g:mn></g:mrow><g:mrow><g:mn>2</g:mn></g:mrow></g:msup></g:mrow></g:math> and in particular develop a unifying theoretical approach, which is inspired by the Grossmann-Lohse theory for wall-bounded turbulence [Grossmann and Lohse, ; ]. The key idea is to split the energy dissipation rate into the different phases of the impact process, in which different physical mechanisms dominate. The theory can consistently and quantitatively account for the <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mi>W</i:mi><i:mi>e</i:mi></i:mrow></i:math> and <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:mrow><k:mi>O</k:mi><k:mi>h</k:mi></k:mrow></k:math> dependences of the maximal impact force and the maximal spreading diameter over the huge parameter space. It also clarifies why viscous dissipation plays a significant role during impact, even for low-viscosity droplets (low <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mi>O</m:mi><m:mi>h</m:mi></m:math>), in contrast to what had been assumed in some prior theories. <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":"17 2 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598984","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":"Metadensity Functional Theory for Classical Fluids: Extracting the Pair Potential","authors":"Stefanie M. Kampa, Florian Sammüller, Matthias Schmidt, Robert Evans","doi":"10.1103/physrevlett.134.107301","DOIUrl":"https://doi.org/10.1103/physrevlett.134.107301","url":null,"abstract":"The excess free energy functional of classical density functional theory depends upon the type of fluid model, specifically on the choice of (pair) potential. This functional is unknown in general and is approximated reliably only in special cases. We present a machine learning scheme for training a neural network that acts as a generic metadensity functional for truncated but otherwise arbitrary pair potentials. Automatic differentiation and neural functional calculus then yield, for one-dimensional fluids, accurate predictions for inhomogeneous states and immediate access to the pair distribution function. The approach provides a means of addressing a fundamental problem in the physics of liquids and for soft matter design: “How do we best invert structural data to obtain the pair potential?” <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":"39 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598986","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}