Strongly enhanced topological quantum phases in dual-surface AlO-encapsulated MnBiTe.

The topological quantum phases in antiferromagnetic topological insulator MnBiTe hold promise for next-generation spintronics, but their experimental realization has been constrained by challenges in preparing high-quality devices. In this work, we report a new wax-assisted exfoliation and transfer method that enables the fabrication of MnBiTe heterostructures with both surfaces encapsulated by AlO. This strategy strongly enhances the transport performances of the topological quantum phases in MnBiTe flakes, which is attributed to the enhancement of magnetism by the AlO layer.

Antiferromagnetic quantum anomalous Hall effect under spin flips and flops.

The interplay between nontrivial band topology and layered antiferromagnetism in MnBiTe has opened a new avenue for exploring topological phases of matter. The quantum anomalous Hall effect and axion insulator state have been observed in odd and even number layers of MnBiTe, and the quantum metric nonlinear Hall effect has been shown to exist in this topological antiferromagnet. The rich and complex antiferromagnetic spin dynamics in MnBiTe is expected to generate new quantum anomalous Hall phenomena that are absent in conventional ferromagnetic topological insulators, but experimental observations are still unknown.

Towards the quantized anomalous Hall effect in AlO-capped MnBiTe.

The quantum anomalous Hall effect in layered antiferromagnet MnBiTe harbors a rich interplay between magnetism and topology, holding a significant promise for low-power electronic devices and topological antiferromagnetic spintronics. In recent years, MnBiTe has garnered considerable attention as the only known material to exhibit the antiferromagnetic quantum anomalous Hall effect. However, this field faces significant challenges as the quantization at zero magnetic field depending critically on fabricating high-quality devices.

Observation of quantum oscillations near the Mott-Ioffe-Regel limit in CaAs.

The Mott-Ioffe-Regel limit sets the lower bound of the carrier mean free path for coherent quasiparticle transport. Metallicity beyond this limit is of great interest because it is often closely related to quantum criticality and unconventional superconductivity. Progress along this direction mainly focuses on the strange-metal behaviors originating from the evolution of the quasiparticle scattering rate, such as linear-in-temperature resistivity, while the quasiparticle coherence phenomena in this regime are much less explored due to the short mean free path at the diffusive bound.

Fabrication-induced even-odd discrepancy of magnetotransport in few-layer MnBiTe.

The van der Waals antiferromagnetic topological insulator MnBiTe represents a promising platform for exploring the layer-dependent magnetism and topological states of matter. Recently observed discrepancies between magnetic and transport properties have aroused controversies concerning the topological nature of MnBiTe in the ground state. In this article, we demonstrate that fabrication can induce mismatched even-odd layer dependent magnetotransport in few-layer MnBiTe.

Tuning the anomalous Nernst and Hall effects with shifting the chemical potential in Fe-doped and Ni-doped CoSnS.

CoSnSis believed to be a magnetic Weyl semimetal. It displays large anomalous Hall, Nernst and thermal Hall effects with a remarkably large anomalous Hall angle. Here, we present a comprehensive study of how substituting Co by Fe or Ni affects the electrical and thermoelectric transport.

Epidemiological and genomic analyses of human isolates of between 2005 and 2021 in Shenzhen, China.

() is an important food-borne zoonotic pathogen that causes swine streptococcosis, which threatens human health and brings economic loss to the swine industry. Three-quarters of human infections are caused by serotype 2. A retrospective analysis of human cases in Shenzhen, a megacity in China, with high pork consumption, between 2005 and 2021 was conducted to understand its genomic epidemiology, pathogen virulence, and drug resistance characteristics.

Population dynamics and antimicrobial resistance of Derby ST40 from Shenzhen, China.

subsp. serovar Derby ( Derby) is one of the most common serotypes responsible for salmonellosis in humans and animals. The two main sequence types (ST) observed in China are ST40 and ST71, with ST40 presently being the most common in Shenzhen.

Isolation of From COVID-19 Swab Kits.

To investigate and characterize the putative contaminant isolated from throat and anal swab samples of patients from three fever epidemic clusters, which were not COVID-19 related, in Shenzhen, China, during COVID-19 pandemic. Bacteria were cultured from throat ( = 28) and anal ( = 3) swab samples from 28 fever adolescent patients. The isolated bacterial strains were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) and the VITEK2 automated identification system.

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law.

The Wiedemann-Franz (WF) law has been tested in numerous solids, but the extent of its relevance to the anomalous transverse transport and the topological nature of the wave function, remains an open question. Here, we present a study of anomalous transverse response in the noncollinear antiferromagnet MnGe extended from room temperature down to sub-kelvin temperature and find that the anomalous Lorenz ratio remains close to the Sommerfeld value up to 100 K but not above. The finite-temperature violation of the WF correlation is caused by a mismatch between the thermal and electrical summations of the Berry curvature and not by inelastic scattering.

Chiral domain walls of MnSn and their memory.

Magnetic domain walls are topological solitons whose internal structure is set by competing energies which sculpt them. In common ferromagnets, domain walls are known to be of either Bloch or Néel types. Little is established in the case of MnSn, a triangular antiferromagnet with a large room-temperature anomalous Hall effect, where domain nucleation is triggered by a well-defined threshold magnetic field.

Unconventional Antiferromagnetic Quantum Critical Point in Ba(Fe_{0.97}Cr_{0.03})_{2}(As_{1-x}P_{x})_{2}.

We have systematically studied physical properties of Ba(Fe_{0.97}Cr_{0.03})_{2}(As_{1-x}P_{x})_{2}, where superconductivity in BaFe_{2}(As_{1-x}P_{x})_{2} is fully suppressed by just 3% of Cr substitution of Fe.

Anomalous Nernst and Righi-Leduc Effects in Mn_{3}Sn: Berry Curvature and Entropy Flow.

We present a study of electric, thermal and thermoelectric response in noncollinear antiferromagnet Mn_{3}Sn, which hosts a large anomalous Hall effect (AHE). Berry curvature generates off-diagonal thermal (Righi-Leduc) and thermoelectric (Nernst) signals, which are detectable at room temperature and invertible with a small magnetic field. The thermal and electrical Hall conductivities respect the Wiedemann-Franz law, implying that the transverse currents induced by the Berry curvature are carried by Fermi surface quasiparticles.