Dong-Hui Xu

Theory for superconductivity in (Tl,K)FexSe2 as a doped Mott insulator

Possible superconductivity in the recently discovered (Tl,K)FexSe2 compounds is studied from the viewpoint of doped Mott insulator. The Mott insulating phase is examined to be preferred in the parent compound at x=1.5 due to the presence of Fe-vacancies. Partial filling of vacancies at the Fe-sites introduces electron carriers and leads to electron-doped superconductivity. By using a two-orbital Hubbard model in the strong-coupling limit, we find that the s-wave pairing is more favorable at small Hunds coupling, and dx2−y2-wave pairing is more favorable at large Hunds coupling.

Effects of Domain Walls in Quantum Anomalous Hall Insulator/Superconductor Heterostructures

In a recent experiment, half-quantized longitudinal conductance plateaus (HQCPs) of height

Photovoltaic anomalous Hall effect in line-node semimetals

\frac{e^2}{2h}

Theory of Spin-Selective Andreev Reflection in the Vortex Core of a Topological Superconductor

have been observed in quantum anomalous Hall (QAH) insulator/superconductor heterostructure transport measurements. It was predicted that these HQCPs are signatures of chiral Majorana edge states. The HQCPs are supposed to appear in the regimes where the Hall conductance

Magnetic impurity in a Weyl semimetal

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Stacking order, interaction, and weak surface magnetism in layered graphene sheets

is quantized. However, experimentally, a pair of the HQCPs appear when the Hall conductance

Possible half-metallic phase in bilayer graphene: Calculations based on mean-field theory applied to a two-layer Hubbard model

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Electric control of inverted gap and hybridization gap in type-II InAs/GaSb quantum wells

is only 80% of the quantized value when dissipative channels appear in the bulk. The dissipative channels in the bulk are expected to induce Andreev reflections and ruin the HQCPs. In this work, we explain how domain walls can cause

Platform for engineering topological superconductors: Superlattices on Rashba superconductors

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Electrically controllable magnetic order in the bilayer Hubbard model on honeycomb lattice: A determinant quantum Monte Carlo study

to deviate from its quantized value and at the same time maintain the quantization of HQCPs. Our work supports the claim that the experimentally observed HQCPs are indeed caused by chiral Majorana modes in the QAH insulator/superconductor heterostructure.