arXiv subjects

Zhibin Qiu

Publications and source records attributed to Zhibin Qiu.

6 recordsLinked to original sources

arXiv2026

A Kagome-Derived Mosaic Lattice Family A3V9Te13 (A = Cs, Rb) with Tunable Strong Electronic Correlations

The pursuit of geometrically frustrated lattices beyond conventional paradigms remains a central challenge in the design of quantum materials. Herein, we report the discovery of the A3V9Te13 (A = Cs, Rb) family of vanadium-based intermetallic compounds, which host a unique two-dimensional Mosaic lattice derived from the Kagome network, composed of an ordered tessellation of triangles, squares, and pentagons. The Cs compound (CVT) exhibits strong electronic correlations, characterized by non-Fermi liquid behavior at low temperatures, an exceptionally large Sommerfeld coefficient, and a bulk phase transition at T* $\approx$ 47 K with possible charge- or spin-related origin. Inspired by pressure-tuning in related Kagome systems, we demonstrate that the electronic ground state of this lattice is exquisitely tunable via chemical pressure. Systematic substitution of Cs with smaller Rb ions suppresses the T* phase transition and the correlated electronic response, ultimately driving the system into a highly frustrated semiconducting ground state without long-range magnetic order down to 60 mK. This work unveils a new structural platform for exploring the interplay between geometric frustration and strong electron correlations, providing a chemically controllable platform for exploring the phase space between distinct correlated electronic states.

cond-mat.mtrl-sci↗

arXiv2026

Dolomite Mineral-Inspired Equilateral Triangular-Lattice Magnets for Quantum Magnetism

Equilateral triangular lattice magnets provide a versatile materials platform for exploring exotic quantum spin phenomena, while their field-tunable magnetic entropy offers opportunities for low-temperature adiabatic demagnetization refrigeration. Inspired by the natural mineral, we proposed a chemical strategy to achieve equilateral TL magnets, leveraging the high crystal symmetry of a large family of dolomite-type materials. As typical examples, the dolomite-type materials SnM(BO3)2 (M = Co, Mn) were synthesized, and structural analysis reveals that Co2+ and Mn2+ ions form equilateral triangular lattices with an A-B-C stacking fashion. The magnetic susceptibilities and specific heat measurements reveal dominant antiferromagnetic interactions, with Neel temperatures of 0.49K for SnCo(BO3)2 and 0.96K for SnMn(BO3)2, respectively. Our results establish the dolomite-type M'M(X)2 (M'and M sites allow various valence states, e.g., +4/+2 or +3/+3; X = CO32- or BO33-) system as a chemically flexible and structurally perfect material platform for exploring frustrated magnetism and low-temperature magnetocaloric applications.

cond-mat.mtrl-sci↗

arXiv2026

Stoichiometry-Controlled Structural Order and Tunable Antiferromagnetism in $\mathrm{Fe}_{x}\mathrm{NbSe_2}$ ($0.05 \le x \le 0.38$)

Transition metal dichalcogenides (TMDs) enable magnetic property engineering via intercalation, but stoichiometry-structure-magnetism correlations remain poorly defined for Fe-intercalated $\mathrm{NbSe_2}$. Here, we report a systematic study of $\mathrm{Fe}_{x}\mathrm{NbSe_2}$ across an extended composition range $0.05 \le x \le 0.38$, synthesized via chemical vapor transport and verified by rigorous energy-dispersive x-ray spectroscopy (EDS) microanalysis. X-ray diffraction, magnetic, and transport measurements reveal an intrinsic correlation between Fe content, structural ordering, and magnetic ground states. With increasing $x$, the system undergoes a successive transition from paramagnetism to a spin-glass state, then to long-range antiferromagnetism (AFM), and ultimately to a reentrant spin-glass phase, with the transition temperatures exhibiting a nonmonotonic dependence on Fe content. The maximum Néel temperature ($T_{\mathrm{N}}$ = $\mathrm{175K}$) and strongest AFM coupling occur at $x=0.25$, where Fe atoms form a well-ordered $2a_0 \times 2a_0 $ superlattice within van der Waals gaps. Beyond $x = 0.25$, the superlattice transforms or disorders, weakening Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions and significantly reducing $T_{\mathrm{N}}$. Electrical transport exhibits distinct anomalies at magnetic transition temperatures, corroborating the magnetic state evolution. Our work extends the compositional boundary of Fe-intercalated $\mathrm{NbSe_2}$, establishes precise stoichiometry-structure-magnetism correlations, and identifies structural ordering as a key tuning parameter for AFM. These findings provide a quantitative framework for engineering altermagnetic or switchable antiferromagnetic states in van der Waals materials.

cond-mat.mtrl-sci↗

arXiv2025

Tunable Multistage Refrigeration via Geometrically Frustrated Triangular Lattice Antiferromagnet for Space Cooling

Low-temperature refrigeration technology constitutes a crucial component in space exploration. The small-scale, low-vibration Stirling-type pulse tube refrigerators hold significant application potential for space cooling. However, the efficient operation of current Stirling-type pulse tube cryocoolers in space cooling applications remains challenging due to the rapid decay of the heat capacity of regenerative materials below 10 K. This study adopts a novel material strategy: using a novel high-spin S = 7/2 magnetic regenerative material, Gd2O2Se, we construct a multistage tunable regenerative material structure to achieve an efficient cooling approach to the liquid helium temperature range. Under substantial geometric frustration from a double-layered triangular lattice, it exhibits two-step specific heat transition peaks at 6.22 K and 2.11 K, respectively. Its ultrahigh specific heat and broad two-step transition temperature range effectively bridge the gap between commercially used high-heat-capacity materials. Experimental verification shows that when Gd2O2Se is combined with Er3Ni and HoCu2 in the Stirling-type pulse tube cryocooler, the cooling efficiency of the pulse tube increases by 66.5 % at 7 K, and the minimum achievable temperature reaches 5.85 K. These results indicate that Gd2O2Se is an ideal magnetic regenerative material for space cooling

cond-mat.mtrl-sci↗

arXiv2023

SE-Bridge: Speech Enhancement with Consistent Brownian Bridge

We propose SE-Bridge, a novel method for speech enhancement (SE). After recently applying the diffusion models to speech enhancement, we can achieve speech enhancement by solving a stochastic differential equation (SDE). Each SDE corresponds to a probabilistic flow ordinary differential equation (PF-ODE), and the trajectory of the PF-ODE solution consists of the speech states at different moments. Our approach is based on consistency model that ensure any speech states on the same PF-ODE trajectory, correspond to the same initial state. By integrating the Brownian Bridge process, the model is able to generate high-intelligibility speech samples without adversarial training. This is the first attempt that applies the consistency models to SE task, achieving state-of-the-art results in several metrics while saving 15 x the time required for sampling compared to the diffusion-based baseline. Our experiments on multiple datasets demonstrate the effectiveness of SE-Bridge in SE. Furthermore, we show through extensive experiments on downstream tasks, including Automatic Speech Recognition (ASR) and Speaker Verification (SV), that SE-Bridge can effectively support multiple downstream tasks.

cs.SD↗

arXiv2022

SRTNet: Time Domain Speech Enhancement Via Stochastic Refinement

Diffusion model, as a new generative model which is very popular in image generation and audio synthesis, is rarely used in speech enhancement. In this paper, we use the diffusion model as a module for stochastic refinement. We propose SRTNet, a novel method for speech enhancement via Stochastic Refinement in complete Time domain. Specifically, we design a joint network consisting of a deterministic module and a stochastic module, which makes up the ``enhance-and-refine'' paradigm. We theoretically demonstrate the feasibility of our method and experimentally prove that our method achieves faster training, faster sampling and higher quality. Our code and enhanced samples are available at https://github.com/zhibinQiu/SRTNet.git.

cs.SD↗