Communications Physics

Abstract Magnetic Resonance Imaging is the gold standard for soft tissue diagnostic imaging but relies on expensive, failure-prone, and loud magnetic field gradients for spatial encoding. Radiofrequency field gradients are a promising alternative, yet they have never achieved frequency encoding, the technique that allows an image to be acquired continuously in milliseconds and without which scan …

Abstract Laguerre-Gaussian (LG) vortex beams with non-zero radial indices provide an additional spatial degree of freedom beyond conventional azimuthal-order vortices, yet their generation in the femtosecond regime has remained experimentally challenging. Here, we report the direct generation of femtosecond radial-mode LG vortex pulses enabled by a mode-locked solid-state oscillator. Higher-order…

Efficient and precise measurement of electromagnetic signals is crucial for both fundamental science and practical applications. Demodulation is a widely used technique for receiving and recovering modulated signals. Here we show a quantum demodulator using two heteronuclear ions to simultaneously detect the amplitudes and frequencies of unknown periodic signals, overcoming the constraint of doub…

Dark matter remains one of the central open questions in particle physics. Astrophysical and cosmological observations imply its existence, yet its underlying nature is unknown. Low-temperature detectors are a powerful technology for detecting dark matter particles, offering excellent energy resolution and low energy thresholds. COSINUS is the only experiment that combines scintillating sodium io…

Abstract Accurate modeling of atomic masses with reliable uncertainty quantification is essential for understanding heavy-element production in astrophysical environments. This remains challenging because uncertainties arise not only from model parameters but also from structural limitations, often leading to underestimation when extrapolating beyond known nuclei. Here, we introduce SPICE, a prob…

Although existing research has confirmed the importance of higher-order structures in identifying key nodes within networks, the challenge remains on how to effectively integrate different types of higher-order information to precisely locate nodes that may be inconspicuous in lower-order structures but play a crucial role in higher-order interactions. To address this challenge, this paper propos…

Abstract The concept of distance is a fundamental idea in graphs and hypergraphs. However, its extension to weighted hypergraphs is challenging, since it may result in inconsistencies, especially if the weights are arbitrarily assigned to the hyperedges. We address this challenge by proposing a general distance measure for weighted hypergraphs. Our measure is well-defined, and it reduces to the c…

The danger of collective failure permeates all levels of human society, making its mitigation critically important. Current theories often rely on a static collective target, which can be unrealistic or insufficient for fostering cooperation. This paper demonstrates a repeated game model featuring a dynamically adjusted governance strategy: if the stage target is met, the target for the next stag…

Abstract Fast quasi-adiabatic driving (FAQUAD) is a central technique in shortcuts to adiabaticity (STA), enabling accelerated adiabatic evolution by optimizing the rate of change of a single control parameter. However, many realistic systems are governed by multiple coupled parameters, where the adiabatic condition depends not only on the local rate of change but also on the path through paramet…

The electrical generation of orbital angular momentum in materials has attracted significant attention due to its fundamental importance and technological potential. Notably, recent experiments on orbital torque and terahertz emission suggest that Cu enables substantial charge-to-orbital interconversion upon oxidation. However, direct evidence of orbital generation in Cu remains elusive. In this …

Self-propelled particles serve as minimal models for emulating the dynamic self-organization of microorganisms, yet most synthetic systems remain limited to a single mode of motion, namely active Brownian particles (ABPs). Here, we present an experimental strategy to encode various persistent random walks in ABPs by combining light-modulated propulsion strength with magnetic control of propulsion…

Abstract Atomic data determined by analysis of observed atomic spectra are essential for plasma diagnostics. For each low-ionisation open d- and f-subshell atomic species, around 10 3 fine structure energy levels can be determined through years of analysis of 10 4 observable spectral lines. We propose a partial automation of this task by casting the analysis procedure as a Markov decision process…

Abstract Understanding when one physical state can be transformed into another is a central problem in quantum information science and thermodynamics. Majorization provides a mathematical tool for describing such transformations. Yet many transitions that are forbidden by majorization can become possible in the presence of a catalyst, an auxiliary system that enables the process without being con…

Precise characterization of atmospheric turbulence is fundamental to free-space optical communications and imaging. While vortex beams are effective turbulence probes, existing sensing methods rely on a spatially integrated one-dimensional (1D) orbital angular momentum (OAM) spectrum, which obscures the heterogeneous nature of atmospheric distortions. Via numerical simulations, here we introduce …

Non-equilibrium Rydberg gases exhibit exotic many-body phases stabilized by the interplay of coherent interactions and dissipation. Strong Rydberg interactions drive sustained limit cycle oscillations, whose robustness, long-range temporal order, and spontaneous time-translation symmetry breaking establish a dissipative time crystal (DTC). Collective self-entrainment in driven ensembles leads to …

Non-Hermitian systems exhibit exponentially amplified spectral sensitivity at higher-order exceptional points (HOEPs), where the eigenvalue response grows with the EP order. Conventional characterization relies on identifying reflection minima, implicitly imposing a fixed-gain constraint. Here, we demonstrate that the attainable order of the EP can be substantially elevated by replacing the fixed…