Pressure-induced magnetic transition and volume collapse in FeAs superconductors: An orbital-selective Mott scenario

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Andreas Hackl - , University of Cologne, Harvard University (Author)
  • Matthias Vojta - , University of Cologne (Author)

Abstract

Motivated by pressure experiments on café2As2, we propose a scenario based on local-moment physics to explain the simultaneous disappearance of magnetism, reduction of the unit cell volume, and decrease in resistivity. In this scenario, the low-pressure magnetic phase derives from Fe moments, which become screened in the paramagnetic high-pressure phase. The quantum phase transition can be described as an orbital-selective Mott transition, which is rendered first order by coupling to the lattice, in analogy to a Kondo volume collapse. Spin-fluctuation driven superconductivity competes with antiferromagnetism and may be stabilized at low temperatures in the highpressure phase. The ideas are illustrated by a suitable mean-field analysis of an Anderson lattice model.

Details

Original languageEnglish
Article number055064
JournalNew journal of physics
Volume11
Publication statusPublished - 29 May 2009
Peer-reviewedYes
Externally publishedYes

Keywords

ASJC Scopus subject areas