Report

Type-II Ising pairing in few-layer stanene

See allHide authors and affiliations

Science  27 Mar 2020:
Vol. 367, Issue 6485, pp. 1454-1457
DOI: 10.1126/science.aax3873

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

A resilient superconductor

Superconductivity typically does not fare well in the presence of magnetic fields, which tend to break the electron pairs that make a material superconducting. However, some materials, such as the recently discovered Ising superconductors, retain their properties in very high magnetic fields. Ising pairing was identified in transition metal dichalcogenides such as molybdenum disulfide and required the breaking of inversion symmetry. Falson et al. have now found a similar resilience to in-plane magnetic fields in another two-dimensional material, few-layer stanene. The band structure of stanene and the lack of inversion symmetry breaking in the system required a distinct theoretical model to explain this property, now dubbed type II Ising pairing.

Science, this issue p. 1454

Abstract

Spin-orbit coupling has proven indispensable in the realization of topological materials and, more recently, Ising pairing in two-dimensional superconductors. This pairing mechanism relies on inversion symmetry–breaking and sustains anomalously large in-plane polarizing magnetic fields whose upper limit is predicted to diverge at low temperatures. Here, we show that the recently discovered superconductor few-layer stanene, epitaxially strained gray tin (α-Sn), exhibits a distinct type of Ising pairing between carriers residing in bands with different orbital indices near the Γ-point. The bands are split as a result of spin-orbit locking without the participation of inversion symmetry–breaking. The in-plane upper critical field is strongly enhanced at ultralow temperature and reveals the predicted upturn.

View Full Text

Stay Connected to Science