arXiv subjects

S. M. Huang

Publications and source records attributed to S. M. Huang.

6 recordsLinked to original sources

arXiv2026

Ferromagnetic Spin Glass State and Anomalous Hall Effect in Topological Semimetal Candidate Mn2Sb2Te5

Materials that intrinsically possess both magnetism and topological states represent a key frontier of quantum materials research. Recently, Mn2(Bi/Sb)2Te5 has emerged as a promising candidate for hosting topological surface states coupled with intrinsic magnetic order, making it a potential magnetic Weyl semimetal. In this study, we investigate the magnetic and transport properties of Mn2Sb2Te5 single crystals. The magnetization measurements reveal a spin glass state with field-induced ferromagnetism. Although heat capacity measurement indicates the absence of long-range order, the intrinsic magnetization in Mn2Sb2Te5 significantly affects its electrical properties, as demonstrated by the anomalous Hall effect. This work provides valuable insights into the magnetism and the electronic properties of Mn2Sb2Te5, establishing Mn2(Bi/Sb)2Te5 system as a compelling platform for exploring the interplay between magnetism and non-trivial band topology, enabling emergent quantum phases and novel transport responses not accessible in non-magnetic systems.

cond-mat.mtrl-sci↗

arXiv2015

Van Hove singularity and ferromagnetic instability in phosphorene

Using Wannier function-based interpolation techniques, we present compelling numerical evidence for the presence of a saddle-point van Hove singularity at the $Γ$ point near the phosphorene Fermi energy. We show that in proximity of the van Hove singularity the spin susceptibility presents the logarithmic temperature dependence typical of Liftshitz phase transitions. Furthermore, we demonstrate that the critical temperature for the ferromagnetic transition can be greatly increased (up to 0.05 K) if strain along the zigzag ridges is applied. Although the ferromagnetic state would be very difficult to experimentally reach, the logarithmic temperature behaviour of the spin susceptibility due to the van Hove singularity is found to persist at much higher temperatures (up to $\sim$97 K).

cond-mat.mes-hall↗

arXiv2010

Cotunneling effects in GaAs vertical double quantum dot

We observed lifting of Coulomb blockade in GaAs vertical double quantum dot with low potential barriers, induced by cotunneling mechanisms at dilution fridge temperature of 10 mK. Several distinct features were observed, compared to single dot case, and appropriate explanation for them was given

cond-mat.mes-hall↗

arXiv2009

Spin bottleneck in resonant tunneling through double quantum dots with different Zeeman splittings

We investigated the electron transport property of the InGaAs/GaAs double quantum dots, the electron g-factors of which are different from each other. We found that in a magnetic field, the resonant tunneling is suppressed even if one of the Zeeman sublevels is aligned. This is because the other misaligned Zeeman sublevels limit the total current. A finite broadening of the misaligned sublevel partially relieves this bottleneck effect, and the maximum current is reached when interdot detuning is half the Zeeman energy difference.

cond-mat.mes-hall↗

arXiv2007

Observation of strong electron dephasing in disordered Cu$_{93}$Ge$_4$Au$_3$ thin films

We report the observation of strong electron dephasing in a series of disordered Cu$_{93}$Ge$_4$Au$_3$ thin films. A very short electron dephasing time possessing very weak temperature dependence around 6 K, followed by an upturn with further decrease in temperature below 4 K, is found. The upturn is progressively more pronounced in more disordered samples. Moreover, a ln$T$ dependent, but high-magnetic-field-insensitive, resistance rise persisting from above 10 K down to 30 mK is observed in the films. These results suggest a nonmagnetic dephasing process which is stronger than any known mechanism and may originate from the coupling of conduction electrons to dynamic defects.

cond-mat.mes-hall↗

arXiv2006

Low energy physical properties of high-Tc superconducting Cu oxides: A comparison between the resonating valence bond and experiments

In a recent review by Anderson and coworkers\cite{Vanilla}, it was pointed out that an early resonating valence bond (RVB) theory is able to explain a number of unusual properties of high temperature superconducting (SC) Cu-oxides. Here we extend previous calculations \cite{anderson87,FC Zhang,Randeria} to study more systematically low energy physical properties of the plain vanilla d-wave RVB state, and to compare results with the available experiments. We use a renormalized mean field theory combined with variational Monte Carlo and power Lanczos methods to study the RVB state of an extended $t-J$ model in a square lattice with parameters suitable for the hole doped Cu-oxides. The physical observable quantities we study include the specific heat, the linear residual thermal conductivity, the in-plane magnetic penetration depth, the quasiparticle energy at the antinode $(π, 0)$, the superconducting energy gap, the quasiparticle spectra and the Drude weight. The traits of nodes (including $k_{F}$, the Fermi velocity $v_{F}$ and the velocity along Fermi surface $v_{2}$), as well as the SC order parameter are also studied. Comparisons of the theory and the experiments in cuprates show an overall qualitative agreement, especially on their doping dependences.

cond-mat.supr-con↗