arXiv subjects

Yunteng Shi

Publications and source records attributed to Yunteng Shi.

4 recordsLinked to original sources

arXiv2025

A non-invasive dry-transfer method for fabricating mesoscopic devices on sensitive materials

Many materials with novel or exotic properties are highly sensitive to environmental factors such as air, solvents, and heat, which complicates device fabrication and limits their potential applications. Here, we present a universal submicron fabrication method for mesoscopic devices using a dry-transfer technique, tailored specifically for sensitive materials. This approach utilizes PMMA masks, combined with a water-dissoluble coating as a sacrificial layer, to ensure that sensitive materials are processed without exposure to harmful environmental conditions. The entire fabrication process is carried out in a glove box, employing dry techniques that avoid air, solvents, and heat exposure, culminating in an encapsulation step. We demonstrate the utility of this method by fabricating and characterizing K2Cr3As3 and WTe2 devices, a one- and two-dimensional material, respectively. The results show that our technique preserves the integrity of the materials, provides excellent contact interfaces, and is broadly applicable to a range of sensitive materials.

cond-mat.mes-hall↗

arXiv2025

Quantized conductance in a CVD-grown nanoribbon with hidden Rashba effect

Quantized conductance in quasi-one-dimensional systems not only provides a hallmark of ballistic transport, but also serves as a gateway for exploring quantum phenomena. Recently, a unique hidden Rashba effect attracts tremendous attention, which arises from the compensation of opposite spin polarizations of a Rashba bilayer in inversion symmetric crystals with dipole fields, such as bismuth oxyselenide ($\mathrm{Bi}_{2}\mathrm{O}_{2}\mathrm{Se}$). However, investigating this effect utilizing conductance quantization is still challenging. Here we report the conductance quantization observed in a chemical vapor deposition (CVD)-grown high-mobility $\mathrm{Bi}_{2}\mathrm{O}_{2}\mathrm{Se}$ nanoribbon, where quantized conductance plateaus up to $44\cdot 2e^{2}/{h}$ ($e$ is the elementary charge, $h$ is the Planck constant, and the factor $2$ results from spin degeneracy) are achieved at zero magnetic field. Due to the hidden Rashba effect, the quantized conductance remains in multiples of $2e^{2}/{h}$ without Zeeman splitting even under magnetic field up to $12$ T. Moreover, within a specific range of magnetic field, the plateau sequence exhibits the Pascal triangle series, namely $(1,3,6,10,15\dots )\cdot 2e^{2}/{h}$, reflecting the interplay of size quantization in two transverse directions. These observations are well captured by an effective hidden Rashba bilayer model. Our results demonstrate $\mathrm{Bi}_{2}\mathrm{O}_{2}\mathrm{Se}$ as a compelling platform for spintronics and the investigation of emergent phenomena.

cond-mat.mes-hall↗

arXiv2025

Diamond-shaped evolution of the superconducting interference pattern in NbTiN weak-link Josephson junctions

The application of in-plane magnetic fields to Josephson junctions enables fundamental exploration of quantum phenomena, including Zeeman-driven 0-$π$ transitions and planar topological superconductivity. However, intrinsic orbital effects arising from nanoscale rippled geometries in practical devices can dominate phase interference signatures, complicating their interpretation. Here, we experimentally probe superconducting interference in NbTiN weak-link Josephson junctions under combined perpendicular and in-plane magnetic fields. The critical supercurrent reveals a distinct diamond-shaped interference pattern, with nodes progressively opening and evolving into V-shaped features, reminiscent of suppression-recovery patterns associated with 0-$π$ transitions. We theoretically analyze the interplay between orbital effects from rippled geometries and non-uniform supercurrent density distributions, demonstrating that their synergistic interaction could reproduce the experimentally observed interference evolution. Our findings elucidate how geometric imperfections and current inhomogeneity cooperatively reshape phase interference, providing critical insights into orbital-dominated phenomena in Josephson systems.

cond-mat.mes-hall↗

arXiv2024

Inverse-current quantum electro-oscillations in a charge-density wave insulator

Quantum magneto-oscillations have long been a vital subject in condensed matter physics, with ubiquitous quantum phenomena and diverse underlying physical mechanisms. Here, we demonstrate the intrinsic and reproducible DC-current-driven quantum electro-oscillations with a periodicity in the inverse of the current (1/I), in quasi-one-dimensional charge-density-wave (CDW) insulators (TaSe$_4$)$_2$I and TaS$_3$ nanowires. Such oscillations manifest in the nearly infinite Fröhlich conductivity region where the undamped CDW flow forms in a finite electric current, and finally disappear after the oscillation index n reaches 1. A systematic investigation on the effect of temperature and magnetic field establishes that the observed electro-oscillations are a coherent quantum phenomenon. We discuss the possibilities of the physical mechanisms, including the formation of sliding-driven inherent Floquet sidebands. Our results introduce a new member in the family of quantum oscillations, and shed light on plausible avenues to explore novel physics and potential applications of coherent density-wave condensates.

cond-mat.mes-hall↗