Two-Dimensional Superconductivity and Anomalous Vortex Dissipation in Newly Discovered Transition Metal Dichalcogenide-Based Superlattices.

Properties of layered superconductors can vary drastically when thinned down from bulk to monolayer owing to the reduced dimensionality and weakened interlayer coupling. In transition metal dichalcogenides (TMDs), the inherent symmetry breaking effect in atomically thin crystals prompts novel states of matter such as Ising superconductivity with an extraordinary in-plane upper critical field. Here, we demonstrate that two-dimensional (2D) superconductivity resembling those in atomic layers but with more fascinating behaviors can be realized in the bulk crystals of two new TMD-based superconductors BaClTaS and BaClTaSe with superconducting transition temperatures 2.

Rashba-splitting-induced topological flat band detected by anomalous resistance oscillations beyond the quantum limit in ZrTe.

Topological flat bands - where the kinetic energy of electrons is quenched - provide a platform for investigating the topological properties of correlated systems. Here, we report the observation of a topological flat band formed by polar-distortion-assisted Rashba splitting in the three-dimensional Dirac material ZrTe. The polar distortion and resulting Rashba splitting on the band are directly detected by torque magnetometry and the anomalous Hall effect, respectively.