SearcharxivSearch

arXiv subjects

Zeyang Xue

Publications and source records attributed to Zeyang Xue.

4 recordsLinked to original sources

Microscopy of cavity-induced density-wave ordering in ultracold gases

We demonstrate high-resolution in-situ imaging of density-wave ordering induced by cavity-mediated interactions in a unitary Fermi gas. We observe long-range spatial correlations throughout the formation of density waves, both for adiabatic preparation and following a quench, with a pattern controlled by the cavity mode structure. Our single-shot microscopic images together with the real-time readout of the cavity photons provide access to atom-photon correlations. We use this capability to investigate order fluctuations as a function of time following a quench and to directly confirm the correspondence between optical and atomic observables. Our system opens rich perspectives, from local patterning to correlation measurements in long-range interacting quantum gases.

cond-mat.quant-gas

WirelessBench: A Tolerance-Aware LLM Agent Benchmark for Wireless Network Intelligence

LLM agents are emerging as a key enabler for autonomous wireless network management. Reliably deploying them, however, demands benchmarks that reflect real engineering risk. Existing wireless benchmarks evaluate single isolated capabilities and treat all errors uniformly, missing both cascaded-chain failures and catastrophic unit confusions (\textit{e.g.}, dB vs.\ dBm). We present \wb{}, the first tolerance-aware, tool-integrated benchmark for LLM-based wireless agents. \wb{} is organized as a three-tier cognitive hierarchy: domain knowledge reasoning (WCHW, 1{,}392 items), intent-driven resource allocation (WCNS, 1{,}000 items), and proactive multi-step decisions under mobility (WCMSA, 1{,}000 items). Moreover, \wb{} is established on three design principles: \emph{(i)}~tolerance-aware scoring with catastrophic-error detection; \emph{(ii)}~tool-necessary tasks requiring a 3GPP-compliant ray-tracing query for channel quality; and \emph{(iii)}~Chain-of-Thought (CoT)-traceable items, where every benchmark item ships with a complete CoT trajectory enabling fine-grained diagnosis of where in the reasoning chain an agent fails. Our numerical results show that the direct-prompting model (GPT-4o) scores $68\%$, trailing a tool-integrated agent ($84.64\%$) by $16.64$\,pp; $23\%$ of errors are catastrophic failures invisible to exact-match metrics. More importantly, the hierarchy decomposes errors into four actionable diagnostic categories that flat evaluation cannot reveal. Code and data: https://wirelessbench.github.io/.

cs.NI

Design and assembly of a cavity microscope with high numerical aperture for quantum simulations

We present the design and assembly of a cavity microscope for quantum simulations with ultracold atoms. The system integrates a high-finesse optical cavity with a pair of high-numerical aperture lenses sharing a common optical axis, enabling simultaneous operation with light close-to-atomic resonance. The system keeps the advantages of a rigid, single-block structure holding the lenses and cavity together, and improves over existing designs by using most of the solid angle left free by the cavity mode for imaging and atomic manipulation purposes. The cavity has a length of \SI{19.786}{\milli\meter}, a finesse of \SI{2.35}{\times 10^4} and operates \SI{214}{\micro\meter} away from the concentric limit, deep in the strong coupling regime. The two lenses offer a numerical aperture of $0.52$ each and maximal optical access in all directions transverse to the cavity axis, compatible with applications in quantum-gas microscopes, micro-tweezer arrays or few-fermions systems, as well as future cavity-assisted quantum simulation protocols demanding sub-cavity-mode control of the atom-cavity coupling.

cond-mat.quant-gas

Simple, highly-stable transfer cavity for laser stabilization based on a carbon-fiber reinforced polymer spacer

We describe the design and operation of a high-stability Fabry-Perot cavity, for laser stabilization in cavity quantum-electrodynamics experiments. Our design is based on an inexpensive and readily available uniaxial carbon-fiber reinforced polymer tube spacer, featuring an ultra-low thermal expansion coefficient. As a result, our $136\mathrm{mm}$-long cavity, which has a finesse of ${5160}$, shows a coefficient of thermal expansion of $1.6 \times 10^{-6}~\mathrm{K}^{-1}$. Enclosing it in a hermetic chamber at room-pressure and using a simple temperature stabilization, we observe absolute frequency excursions over a full day below $50~\mathrm{MHz}$ for a laser operating at $446.785\mathrm{THz}$. The frequency stability is limited by the imperfect thermal isolation from the environment and can be corrected using a built-in piezo-electric actuator. In addition, we discuss a different variant of this design and identify future improvements. Our system provides a cost-effective and robust solution for transferring laser stability over different wavelengths, as well as for linewidth reduction or spectral filtering of CW laser sources for applications in quantum science.

physics.atom-ph