Tunable Mirror‐Symmetric Type‐III Ising Superconductivity in Atomically‐Thin Natural Van der Waals Heterostructures
Year: 2024
Type: article
Abstract: Van der Waals (vdW) crystals with strong spin‐orbit coupling (SOC) provide great opportunities for exploring unconventional 2D superconductors, wherein new pairing states emerge due to the interplay of SOC with crystalline symmetries, electronic correlations, quenched disorders and external modulation forces, etc. Here, a distinct mirror‐symmetry protected Ising pairing state with unprecedented Γ‐ and M‐valley symmetries in natural vdW heterostructures (vdWH) of interweaving tetragonal SnSe and trigonal 1H‐TaSe2 monolayers is reported, in which the unidirectional lattice interlocking effectively suppresses the K‐valley Ising pairing mechanism by incommensurate charge‐density‐wave (CDW) transitions. In the 2D limit of an TaSe2/SnSe bilayer with intact basal mirror symmetry (Mz), the mirror‐symmetric vdWH Ising superconductors show anomalous in‐plane magnetic field B‖‐controlled enhancements in the critical temperature Tc, which is completely absent for multilayer vdWHs with broken Mz induced by orthorhombic stacking between nearest‐neighbour TaSe2 monolayers. The experimental observations consistently reveal a mirror symmetry‐protected type‐III Ising state in the inversion asymmetric lattice of 1H‐TaSe2, which is predicted to be a mixture of spin‐singlet and spin‐triplet states.
Source: Advanced Materials
Institutions: State Key Laboratory of Silicon Materials, Zhejiang University, Chinese Academy of Sciences, Shanghai Institute of Microsystem and Information Technology, State Key Laboratory of Functional Materials for Informatics, University of Science and Technology of China, National Synchrotron Radiation Laboratory, ShanghaiTech University, High Magnetic Field Laboratory, National Institute for Materials Science
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4405025518