Free surfaces recast superconductivity in few-monolayer MgB₂: Combined first-principles and ARPES demonstration.

ABSTRACT: Two-dimensional materials are known to harbour properties very different from those of their bulk counterparts. Recent years have seen the rise of atomically thin superconductors, with a caveat that superconductivity is strongly depleted unless enhanced by specific substrates, intercalants or adatoms. Surprisingly, the role in superconductivity of electronic states originating from simple free surfaces of two-dimensional materials has remained elusive to date. Here, based on first-principles calculations, anisotropic Eliashberg theory, and angle-resolved photoemission spectroscopy (ARPES), we show that surface states in few-monolayer MgB₂ make a major contribution to the superconducting gap spectrum and density of states, clearly distinct from the widely known, bulk-like σ- and

SUBMITTER: Bekaert J 

PROVIDER: S-EPMC5663715 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature