Kejing Ran

Drive the Dirac electrons into Cooper pairs in SrxBi2Se3

Topological superconductors are a very interesting and frontier topic in condensed matter physics. Despite the tremendous efforts in exploring topological superconductivity, its presence is however still under heavy debate. The Dirac electrons have been proven to exist on the surface of a topological insulator. It remains unclear whether and how the Dirac electrons fall into Cooper pairing in an intrinsic superconductor with the topological surface states. Here we show the systematic study of scanning tunnelling microscope/spectroscopy on the possible topological superconductor SrxBi2Se3. We first demonstrate that only the intercalated Sr atoms can induce superconductivity. Then we show the full superconducting gaps without any in-gap density of states as expected theoretically for a bulk topological superconductor. Finally, we find that the surface Dirac electrons will simultaneously condense into the superconducting state within the superconducting gap. This vividly demonstrates how the surface Dirac electrons are driven into Cooper pairs.

High-pressure magnetization and NMR studies of α−RuCl3

We report high-pressure magnetization and

Evidence for a Dirac nodal-line semimetal in SrAs 3

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Discovery of coexisting Dirac and triply degenerate magnons in a three-dimensional antiferromagnet

Cl NMR studies on

Recent progress on magnetic-field studies on quantum-spin-liquid candidates

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Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of α−RuCl3

-RuCl

Direct visualization of a two-dimensional topological insulator in the single-layer 1T′−WTe2

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Spin-Glass Ground State in a Triangular-Lattice Compound YbZnGaO_{4}.

with pressure up to 1.5~GPa. At low pressures, the magnetic ordering is identified by both the magnetization data and the NMR data, where the

Ultralow-Temperature Thermal Conductivity of the Kitaev Honeycomb Magnet α-RuCl 3 across the Field-Induced Phase Transition

T_N

Identifying the triangular-lattice compound YbZnGaO

shows a concave shape dependence with pressure. These data suggest stacking rearrangement along the