Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

4-1-2015

Journal or Book Title

Physical Review B

Volume

91

Issue

14

First Page

140502(R)

DOI

10.1103/PhysRevB.91.140502

Abstract

We use a tunable laser angle-resolved photoemission spectroscopy to study the electronic properties of the prototypical multiband BCS superconductor MgB2. Our data reveal a strong renormalization of the dispersion (kink) at ∼65meV, which is caused by the coupling of electrons to the E2g phonon mode. In contrast to cuprates, the 65 meV kink in MgB2 does not change significantly across Tc. More interestingly, we observe strong coupling to a second, lower energy collective mode at a binding energy of 10 meV. This excitation vanishes above Tc and is likely a signature of the elusive Leggett mode.

Comments

This article is published as Mou, Daixiang, Rui Jiang, Valentin Taufour, Rebecca Flint, S. L. Bud'ko, P. C. Canfield, J. S. Wen, Z. J. Xu, Genda Gu, and Adam Kaminski. "Strong interaction between electrons and collective excitations in the multiband superconductor MgB 2." Physical Review B 91, no. 14 (2015): 140502. DOI: 10.1103/PhysRevB.91.140502. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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