Physics
Real-Time ECH Profile Control Algorithm Validated on DIII-D Tokamak
A novel ECH Optimization (ECHO) algorithm, combining a neural network surrogate of TORBEAM with a genetic optimizer, achieves real-time control of ECH deposition profiles on DIII-D. This system optimizes gyrotron parameters for heating and current drive, demonstrating robust performance and reliabil…
Quantized Time Statistics in Quantum Walks Under Multi-Channel Monitoring
This paper investigates the quantization of time statistics in quantum walks subjected to weak rank-K measurements. It demonstrates that under multi-channel strong or indirect monitoring, the mean return time within the projected subspace quantizes, extending the known quantization of mean return ti…
Phase-Shift Interferometry Turns a 123-Meter Optical Cavity into a Sub-Micron Absolute Strainmeter
This work demonstrates a dual-laser phase-sensing technique that converts the free spectral range variation of a 123-meter high-finesse cavity into a continuous absolute length measurement with sub-micron precision. By phase-locking a second laser at a fixed frequency offset from a resonance-locked …
Certifying Nonclassical Proper-Time Histories with Quantum Clocks and Ramsey Protocols
This work addresses the certification of nonclassical proper-time histories using quantum clocks. It establishes that acquiring relativistic phases from proper-time differences does not inherently guarantee nonclassical behavior, framing the distinction as a channel-certification problem. The resear…
Matrix Phase-Space Representations Enhance Quantum Simulation Accuracy
This paper introduces matrix phase-space, a general phase-space representation incorporating global quantum symmetries. By projecting the basis onto a reduced Hilbert space, this method aims to decrease sampling errors in quantum simulations. It unifies existing phase-space techniques and offers a r…
Order-Selective Isolation of Higher-Order Nonlinear Spectroscopic Signals via Computational Tracking
A new computational strategy integrating rotating-frame acquisition and frame-shift tracking enables the isolation of higher-order nonlinear spectroscopic signals, specifically demonstrating the separation of a 7th-order response from 3rd-order components in rubidium vapor. This technique facilitate…
SH0-mode overtone SAW resonators on thin-film LiNbO3 boost acousto-optic overlap by >10x over Rayleigh modes
The authors propose shear-horizontal (SH0) SAW resonators on thin-film lithium niobate to dramatically improve intermodal acousto-optic modulation efficiency. By optimizing cut angle, wavelength, and IDT electrode thickness, they report acousto-optic overlap factors improved by over an order of magn…
Noise suppression via QZD and DD can achieve Heisenberg limit where QEC falls short
This paper provides necessary and sufficient conditions for when quantum Zeno dynamics (QZD) and dynamical decoupling (DD) can suppress noise and enable Heisenberg-limited sensitivity in quantum metrology. For Markovian noise, the authors prove that QZD/DD can achieve the Heisenberg limit in scenari…
Exploring Exotic Spin-Dependent Interactions Mediated by Axion-Like Particles Beyond the Standard Model
This review outlines the theoretical basis for exotic spin-dependent interactions mediated by new, light particles like Axion-Like Particles (ALPs). These interactions, proposed by theories beyond the Standard Model, may address issues like the strong CP problem and contribute to understanding dark …
Kerr Nonlinearity Enables Nonreciprocal Transparency and Controllable Slow/Fast Light in Hybrid Magnomechanics
This paper proposes that the magnon Kerr nonlinearity in a hybrid cavity magnomechanical system (two YIG spheres plus a mechanical resonator) can induce direction-dependent frequency shifts, enabling nonreciprocal transparency and Fano resonances. The Kerr effect modifies interference pathways among…
VALO1.0: New Monte Carlo photon PDFs from global QCD analysis of F2^γ
The VALO1.0 analysis presents new parton distribution functions (PDFs) for real photons determined from a global QCD fit to photon structure function F2^γ data from e+e- scattering, at both LO and NLO. By using Monte Carlo replica methods, the authors propagate experimental uncertainties into the PD…
Nuclear Parton Distributions and Shadowing: A Review of Theory, Experiment, and Future Directions
This review focuses on nuclear parton distribution functions (PDFs), particularly in the small-x regime where nuclear shadowing is prominent. It synthesizes experimental evidence and theoretical models explaining these modifications, alongside model-agnostic PDF extractions that support collinear fa…
In Situ Reflectometry for High-Efficiency Fiber Cavity Mirror Substrate Fabrication
This work introduces a novel fabrication method for fiber cavity mirror substrates that enhances mode matching efficiency. By employing in situ reflectometry to pre-select fibers and guide CO2 laser ablation, the technique ensures high compatibility with cavity modes. This approach significantly inc…
Quantum Post-Selection as an Alternative to Dark Energy: Cosmic Acceleration Without a Cosmological Constant
Cosmic acceleration may emerge as a macroscopic quantum effect from post-selection and coarse-graining, bypassing the need for a cosmological constant, dark energy, or modified gravity. This minimal model reproduces standard early-universe behavior and fits supernova and cosmic chronometer data comp…
Trapped $^{40}$Ca$^+$ Ions Achieve High-Fidelity Entanglement for Quantum Repeaters
This work demonstrates a quantum repeater segment utilizing free-space coupled, co-trapped $^{40}$Ca$^+$ ions. Photons emitted by these ions were converted to the telecom-C band and interfered after 440m of fiber transmission, enabling entanglement generation between quantum memories with a fidelity…
Gate-Tunable Spin-Valley Transport in Monolayer WSe$_2$ via Carrier Velocity Engineering
This work theoretically investigates spin- and valley-resolved quantum transport in monolayer WSe$_2$ using a massive Dirac Hamiltonian. It demonstrates that modulating carrier velocity and scalar potential within a barrier region allows for tunability of transport properties, including anisotropy a…
Minimality Proof for Stabilizer ZX-Calculus Rewrite Rules
This paper establishes the minimality of the stabilizer ZX-calculus rewrite rule set by proving the necessity of two previously unverified rules: the red/green compact-structure coincidence and the bialgebra law. A countermodel-style argument, relative to the Backens-Perdrix-Wang connectivity meta-r…
Neutrino Many-Body Simulations Face Divergent Timescales and High Quantum Resource Costs
This work compares the standard quantum kinetic framework (which ignores multi-body correlations) against the full many-body Hamiltonian approach for modeling collective neutrino oscillations in dense astrophysical environments, finding significant differences in both timescales and asymptotic behav…
Handbook of Error-Correcting Codes: A Catalog of Classical and Quantum Methods
This work presents a handbook version of "The Error Correction Zoo," a comprehensive catalog of error-correcting codes for both classical and quantum information. It classifies codes by their symbolic usage and maps their interrelations to mathematical structures like lattices and sphere packings, a…
Photon Statistics Reveal Light-Matter Interactions and Material Properties in Optical Cavities
This work demonstrates that polarization-resolved photon statistics, specifically the second-order coherence function $g^{(2)}$, serve as a diagnostic tool for probing light-matter coupling in optical cavities. By correlating $g^{(2)}$ measurements with material properties through functions like the…
Mach's Principle Analog Observed in Atomic Transition Probabilities Under Circular Motion
This paper explores atomic transition probabilities in atom-mirror systems, comparing two setups: a static cylindrical mirror with a rotating atom, and a rotating cylindrical mirror with a static atom. The authors found a structural similarity in the transition probabilities between these two scenar…
Non-Hermiticity Generically Drives 1D Dirac Criticality
Li et al. demonstrate that non-Hermitian delocalized states in one dimension are generically critical, belonging to the random Dirac fermion universality class — a phenomenon that in Hermitian systems only occurs at fine-tuned transitions. By connecting spectral winding to topological Anderson trans…
LHCb measures Bc+ semileptonic branching fraction ratio, consistent with Standard Model
The LHCb experiment has measured the ratio of semileptonic branching fractions $\mathcal{R}(J/\psi) \equiv \mathcal{B}(B_c^+ \to J/\psi \tau^+ \nu_{\tau})/\mathcal{B}(B_c^+ \to J/\psi \mu^+ \nu_{\mu})$ using 5.4 fb$^{-1}$ of 13 TeV proton-proton collision data. The measured value is $0.51 \pm 0.12 \…
Tensor Decomposition of Energy-Momentum Correlators: A Path to Efficient Lattice QCD Calculations
Moore and Winter derive the general functional form of the energy-momentum tensor two-point function in Euclidean coordinate space at both zero and finite temperature. They decompose the full correlator into fundamental tensorial structures based on residual rotational symmetry, then use energy-mome…
Radio-Frequency Powering Systems for Accelerators: A Review of Technologies and Principles
This review provides a foundational overview of radio-frequency (RF) powering systems for accelerators, encompassing vacuum tube technologies (tetrodes, klystrons, IOTs) and transistors. It details essential principles of RF power transmission, including combining/splitting systems and transmission …
Universal Scaling Law for Quantum Battery Collective Charging
This paper establishes a universal scaling law for the collective charging of quantum batteries, demonstrating that the ergotropy-to-energy ratio approaches unity at a rate of at least N^{-1}, independent of microscopic details. The research also shows that this universal scaling can be surpassed, a…
Directional Quantum Squeezing Enables Selective Two-Photon Emission in Coupled Optical Resonators
This paper investigates one-way photon-photon bundle emission in a coupled optical resonator system with a two-level atom, driven by directional quantum squeezing. The technique induces asymmetric frequency detuning and photon hopping, enabling directional excitation of two-photon super-Rabi oscilla…
Analytical Evaluation of Quantum Radar Architectures: Performance, Limitations, and Optimal Design
This paper provides an analytical framework for evaluating quantum radar architectures, specifically single-photon direct-detection and quantum-entangled noise radars. It derives expressions for maximum detection range, presenting quantum-entangled noise radar as an enhanced direct-detection system.…
Topological Scattering and Spectral Control in a Qubit-SSH Photonic Lattice Hybrid
This work presents a theoretical framework for analyzing single-photon scattering in a hybrid system comprising a superconducting qubit coupled to a Su-Schrieffer-Heeger (SSH) photonic lattice with tunable loss/gain. The study derives an energy-dependent scattering matrix in real space, revealing ho…
Graphene Flake Dynamics: Benchmarking Quantum Simulations with Interaction-Driven Phenomena
This work investigates interaction-driven dynamics in finite graphene flakes using an interacting tight-binding model and real-time evolution. It finds that periodic flakes are efficiently simulated by low-order excitations, whereas confined geometries require higher-order processes. The single-part…
Optimal Quantum Algorithms for Unitary Channel Testing Under Depolarizing Noise
Ghosh, Jackson, and Datta present optimal quantum algorithms (with matching lower bounds) for testing whether an unknown quantum channel matches a target unitary under the assumption that any deviation is depolarizing noise. The exact testing problem has query complexity Θ(1/ε), while the relaxed (ε…
Experimental Realization of Quantum Noise Cancellation and Capacity Superactivation via Channel Superposition
This paper demonstrates a method for noise cancellation in quantum channels by superposing their corresponding Stinespring dilation unitaries. The authors experimentally realized the cancellation of dephasing channels using NMR, recovering quantum coherence. They also showed the superactivation of q…
Surface Dynamics Drive Scalar Pair Creation: Beyond the Leading Order
This work computes pair creation amplitudes for a real scalar field under time-dependent surface deformations with Dirichlet boundary conditions, extending results to fourth order in the surface's deviation from planarity. The authors derive the angular dependence of vacuum-to-pair emission rates as…
Higher-Order Exceptional Surfaces via Dissipative Coupling Enable Enhanced Quantum Sensing
This paper proposes a four-channel dissipative coupling model that realizes fourth-order exceptional surfaces and second-order exceptional volumes, enabling a fourth-order sensitivity response to perturbations that significantly exceeds what is possible with conventional second-order exceptional poi…
Random Matrix Theory for Chaotic Wave Scattering and Transport in Open Systems
This review explores the application of random matrix theory to chaotic wave scattering and transport in open systems. It highlights how non-Hermitian Hamiltonians can model these phenomena, with key observables including scattering and reaction matrices, time delays, and complex resonances. The wor…
Th-229 Nuclear Isomer Enables Next-Generation Precision Clocks
The Th-229 nuclear isomeric state, possessing the lowest known nuclear excitation energy, is poised to enable unprecedentedly accurate nuclear optical clocks achievable with present-day laser technology. Recent breakthroughs in direct laser excitation have catalyzed intensified research, focusing on…
Antiferromagnetic domain walls in Sr2IrO4 migrate at supersonic speeds via purely electronic mechanism
Using laser pump-probe coherent X-ray diffraction imaging, researchers directly measured antiferromagnetic domain wall motion in Sr2IrO4 at 100 K and found velocities of 3×10⁶ m/s — far exceeding acoustic (sound) velocities in the material. This supersonic migration is attributed to a purely electro…
MAFS: A Parameter-Economical Alternative to Froggatt-Nielsen for Fermion Mass Hierarchies
The authors introduce a framework called Maximal Abelian Flavor Symmetries (MAFS) that explains the observed hierarchies in quark and lepton masses and mixing angles using a minimal set of small parameters—one per fermion multiplet. Unlike Froggatt-Nielsen, MAFS has no free charge assignments, makin…
Argon seeding enables GW-class fusion power with divertor detachment in ARC
Integrated core-edge modeling of the ARC tokamak shows that Argon seeding can simultaneously achieve fusion power approaching 1 GW and divertor temperatures below 2 eV, satisfying detachment requirements. Performance is strongly sensitive to separatrix density (750-1000 MW range) but only weakly dep…
CASCO Simulation and Experimental Validation of Pulsating Heat Pipes: Nucleation Barriers and Stopover Regimes
This work investigates the steady-state operation of pulsating heat pipes (PHPs) using the CASCO simulation software, version 4. Experimental validation was conducted on two prototypes to analyze the impact of surface properties and stopovers. An optimal nucleation barrier was identified, which mini…
Elastoinertial Effects Govern Dynamic Nonlinearity in Soft Hair Beds
This work characterizes the transient rheological response of elastic hair beds to oscillatory shear flows. The coupled hair-fluid interaction yields a nonlinear dynamic response dependent on frequency and amplitude, featuring a crossover between stress-lagging and stress-leading regimes influenced …
Numerical Study of Oscillatory Magnetic Reconnection Driven by Alternating Currents in a Laboratory Plasma
This numerical experiment investigates oscillatory magnetic reconnection in a laboratory plasma using the MPI-AMRVAC framework. The study details the dynamics of current sheet formation and evolution, driven by alternating current-induced magnetoacoustic waves perturbing a magnetic null. Key finding…
Preskill on the Entropy Paradox: Beloved in Theory, Fought in Practice
John Preskill, a leading theoretical physicist and quantum information scientist, offers a pithy observation on the dual nature of entropy: it is a foundational and celebrated concept in physics and information theory, yet virtually all practical engineering and scientific effort — from thermodynami…
Geometric Framework Completes Thermodynamic Relaxation Description
This paper introduces a novel thermo-geometric measure, based on the Rayleigh quotient, to model relaxation processes. It reframes relaxation as a competition between entropic stiffness and frictional dissipation, thereby completing the thermodynamic geometry framework. The authors demonstrate this …
Improved Classical Density Functionals via Test Particle Sum Rules
This paper details an extension of a novel approach for developing classical density functionals for hard-sphere (HS) fluids. By integrating test-particle sum rules for excess chemical potential and isothermal compressibility, the authors optimize the parameters in Lutsko's fundamental measure theor…
Understanding Phase Transitions Through a Discretized Fluid Model
This video introduces the liquid-vapor model, a discretized fluid simulation, to explain phase transitions. It delves into the Boltzmann formula, explaining how statistical mechanics and the concept of free energy govern the behavior of matter at different temperatures and chemical potentials. The m…
Proposal for an "Anderson solid" phase in 2D bilayer graphene
A recent STM experiment observed three distinct quantum phases in 2D bilayer graphene under a strong magnetic field. This paper argues that one of these phases, a spatially random localized phase at low filling, is consistent with the proposed disorder-dominated strongly localized amorphous "Anderso…
Macroscopic Quantum Phenomena: From Physics Education to Nobel Prize-Winning Research
John Martinis discusses his journey from an early interest in science nurtured by his parents to his Nobel Prize-winning work in macroscopic quantum phenomena. He emphasizes the importance of asking questions, the role of collaboration and argument in scientific discovery, and the necessity of rigor…