arXiv subjects

Li-Li Yang

Publications and source records attributed to Li-Li Yang.

3 recordsLinked to original sources

arXiv2026

A Unified Charge-Dependent Modulation Model for AMS-02 Proton and Antiproton Fluxes during Solar Minimum

We develop a unified charge-dependent solar modulation model by solving the three-dimensional Parker transport equation, incorporating a realistic wavy heliospheric current sheet to treat drift effects self-consistently. Using a local interstellar spectrum from GALPROP constrained by Voyager data, we fit the model to time-resolved proton and antiproton fluxes measured by the Alpha Magnetic Spectrometer - 02 (AMS-02) during the solar-quiet period (May 2011 to June 2022). To enable rapid parameter scans, we employ neural-network-based surrogate models to compute propagation and modulation matrices efficiently. The results demonstrate that the model simultaneously describes the observed proton and antiproton fluxes with physically reasonable parameters, providing a unified account of charge-dependent modulation.

astro-ph.HE↗

arXiv2024

The Hall effects of vortex light in optical materials

For light, its spin can be independent of the spatial distribution of its wave function, whereas its intrinsic orbital angular momentum does depend on this distribution. This difference suggests that the spin Hall effect might differ from the orbital Hall effect as light propagates through optical materials. In this paper, we model optical materials as curved space-time and investigate light propagation in two specific materials by solving the covariant Maxwell equations. We find that the trajectory of light with spin $\sigma$ and intrinsic orbital angular momentum $\ell$ deviates from that of light without angular momentum ($\sigma=0$ and $\ell=0$) by an angle $\theta_{\sigma,\ell} \propto 2\sigma+\ell$. In particular, the contribution of spin $\sigma$ to angle $\theta_{\sigma,\ell}$ is twice that of the intrinsic orbital angular momentum $\ell$, highlighting their differing effects on light propagation in optical materials. Furthermore, this angle $\theta_{\sigma,\ell}$ could potentially be observed experimentally, enhancing our understanding of the role of angular momentum in light propagation.

physics.optics↗

arXiv2011

Solid-State Optimal Phase-Covariant Quantum Cloning Machine

Here we report an experimental realization of optimal phase-covariant quantum cloning machine with a single electron spin in solid state system at room temperature. The involved three states of two logic qubits are encoded physically in three levels of a single electron spin with two Zeeman sub-levels at a nitrogen-vacancy defect center in diamond. The preparation of input state and the phase-covariant quantum cloning transformation are controlled by two independent microwave fields. The average experimental fidelity reaches 85.2% which is very close to theoretical optimal fidelity 85.4% and is beyond the bound 83.3% of universal cloning.

quant-ph↗