arXiv subjects

Zhuoqi Li

Publications and source records attributed to Zhuoqi Li.

6 recordsLinked to original sources

arXiv2026

RePro: Proof-Verified Benchmark Rewriting for Reliable Evaluation of LLM Mathematical Problem Solving

Data contamination undermines the reliable evaluation of large language models (LLMs) on mathematical problem solving. While rewriting-based evaluation mitigates memorization, existing methods lack guarantees of problem validity and answer correctness. We propose Proof-Verified Benchmark Rewriting (RePro), the first framework to integrate Lean-oriented neural automated theorem provers (ATPs) into benchmark rewriting, which rewrites problems and regenerates answers with correctness ensured by Lean-verified proofs. Experiments on GSM8K and MATH show that RePro's retained rewritten instances achieve 100% well-definedness, feasibility, and answer correctness, while existing methods still produce invalid or incorrect instances. Moreover, several models exhibit accuracy drops on proof-verified rewritten benchmarks, suggesting that their performance is sensitive to surface-level and structural variations and may partly reflect memorization effects. Our source code and data are available at https://github.com/AI4Engi/RePro.

cs.CL↗

arXiv2026

Robust two-dimensional surface superconductivity and vortex lattice in the Weyl semimetal $γ$-PtBi$_2$

The layered compound $γ$-PtBi$_2$ is a topological semimetal with Fermi arcs at the surface joining bulk Weyl points. Recent work has found signatures of surface superconductivity consisting of gap openings compatible with a critical temperature orders of magnitude larger than the bulk value. However, no superconducting vortices have been identified, raising questions about the robustness of the phase coherence. Here we use very low temperature Scanning Tunneling Microscopy (STM) and find robust superconductivity with T$_C=$2.9 K and H$_{C2}\approx$1.8 T linked to the Fermi arcs. We observe quantized superconducting vortices and the Josephson effect, demonstrating two-dimensional macroscopic quantum phase coherence.

cond-mat.supr-con↗

arXiv2025

Superconducting dome and structural changes in LaRu$_3$Si$_2$ under pressure

LaRu$_3$Si$_2$ is of current research interest as a kagome metal with a superconducting transition temperature, $T_c\sim$7 K and higher temperature charge density wave (CDW) orders. Here we report electrical transport and X-ray diffraction measurements on LaRu$_3$Si$_2$ under pressure up to 65 GPa and 35 GPa respectively. The superconducting transition temperature $T_c$ first gets slightly enhanced and reaches a maximum $\sim$8.7 K at $\sim$8.5 GPa. With further applied pressure, $T_c$ is initially gradually suppressed, then more rapidly suppressed, followed by gradual suppression, revealing a superconducting dome. Two possible pressure-induced structural phase transitions are also observed at room temperature, from original hexagonal phase to another hexagonal structure above $\sim$11.5 GPa, and further to a structure with lower symmetry above $\sim$23.5 GPa. These transition pressures roughly correlate with features found in our pressure dependent transport data.

cond-mat.supr-con↗

arXiv2025

Topography of Fermi Arcs in t-PtBi$_2$ Using High Resolution Angle-resolved Photoemission Spectroscopy

We use high resolution angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) to investigate the electronic structure of trigonal phase ${\rm PtBi_2}$ (t-${\rm PtBi_2}$), a proposed Weyl semimetal that is expected to exhibit topological Fermi Arcs. Our ARPES data elucidates the topography of these objects and confirms their Fermi arc character. The arcs are formed by surface bands that have fairly flat bottom located very close to the chemical potential $\sim$ 6-8 meV, before they merge with bulk bands at higher binding energy. Comparison of the ARPES data with DFT calculations shows good agreement about their location and topography. Data acquired at low temperatures does not show any signatures of superconductivity down to 3 K in terms of expected changes in dispersion due to formation of Bogoliubov quasiparticles or superconducting gap in form of reliable shifts of peaks in energy distribution curves.

cond-mat.mes-hall↗

arXiv2024

Long-range magnetic order induced surface state in GdBi and DyBi

The recent discovery of unconventional surface-state pairs, which give rise to Fermi arcs and spin textures, in antiferromagnetically ordered rare-earth monopnictides attracted the interest in these materials. We use angle-resolved photoemission spectroscopy (ARPES) measurements in conjunction with density functional theory (DFT) calculations to investigate the evolution of the electronic structure of GdBi and DyBi. We find that new surface states, including a Dirac cone, emerge in the AFM state. However, they are located along a direction in momentum space that is different than what was found in NdSb, NdBi, and CeBi. The observed changes in the electronic structure are consistent with the presence of AFM-II-A type order.

cond-mat.str-el↗

arXiv2017

UNBIAS PUF: A Physical Implementation Bias Agnostic Strong PUF

The Physical Unclonable Function (PUF) is a promising hardware security primitive because of its inherent uniqueness and low cost. To extract the device-specific variation from delay-based strong PUFs, complex routing constraints are imposed to achieve symmetric path delays; and systematic variations can severely compromise the uniqueness of the PUF. In addition, the metastability of the arbiter circuit of an Arbiter PUF can also degrade the quality of the PUF due to the induced instability. In this paper we propose a novel strong UNBIAS PUF that can be implemented purely by Register Transfer Language (RTL), such as verilog, without imposing any physical design constraints or delay characterization effort to solve the aforementioned issues. Efficient inspection bit prediction models for unbiased response extraction are proposed and validated. Our experimental results of the strong UNBIAS PUF show 5.9% intra-Fractional Hamming Distance (FHD) and 45.1% inter-FHD on 7 Field Programmable Gate Array (FPGA) boards without applying any physical layout constraints or additional XOR gates. The UNBIAS PUF is also scalable because no characterization cost is required for each challenge to compensate the implementation bias. The averaged intra-FHD measured at worst temperature and voltage variation conditions is 12%, which is still below the margin of practical Error Correction Code (ECC) with error reduction techniques for PUFs.

cs.AR↗