Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

1-1-2014

Journal or Book Title

Physical Review B

Volume

89

Issue

2

First Page

020511(R)

DOI

10.1103/PhysRevB.89.020511

Abstract

We use angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic structure of CaFe2As2 in the collapsed tetragonal (CT) phase. This unusual phase of iron arsenic high-temperature superconductors was hard to measure as it exists only under pressure. By inducing internal strain, via the postgrowth thermal treatment of single crystals, we were able to stabilize the CT phase at ambient pressure. We find significant differences in the Fermi surface topology and band dispersion data from the more common orthorhombic-antiferromagnetic or tetragonal-paramagnetic phases, consistent with electronic structure calculations. The top of the hole bands sinks below the Fermi level, which destroys the nesting present in parent phases. The absence of nesting in this phase, along with an apparent loss of Fe magnetic moment, are now clearly experimentally correlated with the lack of superconductivity in this phase.

Comments

This article is published as Dhaka, R. S., Rui Jiang, S. Ran, Sergey L. Bud'ko, Paul C. Canfield, Bruce N. Harmon, Adam Kaminski, Milan Tomić, Roser Valentí, and Yongbin Lee. "Dramatic changes in the electronic structure upon transition to the collapsed tetragonal phase in CaFe 2 As 2." Physical Review B 89, no. 2 (2014): 020511. DOI: 10.1103/PhysRevB.89.020511. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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