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arXiv · 1705.02286

Electronic anisotropies revealed by detwinned ARPES measurements of FeSe

Matthew D Watson·Amir A. Haghighirad·Luke C. Rhodes·Moritz Hoesch·Timur K. Kim
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Abstract

We report high resolution ARPES measurements of detwinned FeSe single crystals. The application of a mechanical strain is used to promote the volume fraction of one of the orthorhombic domains in the sample, which we estimate to be 80$\%$ detwinned. While the full structure of the electron pockets consisting of two crossed ellipses may be observed in the tetragonal phase at temperatures above 90~K, we find that remarkably, only one peanut-shaped electron pocket oriented along the longer $a$ axis contributes to the ARPES measurement at low temperatures in the nematic phase, with the expected pocket along $b$ being not observed. Thus the low temperature Fermi surface of FeSe as experimentally determined by ARPES consists of one elliptical hole pocket and one orthogonally-oriented peanut-shaped electron pocket. Our measurements clarify the long-standing controversies over the interpretation of ARPES measurements of FeSe.

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Matthew D Watson, Amir A. Haghighirad, Luke C. Rhodes, Moritz Hoesch, Timur K. Kim. 2017-10-26. Electronic anisotropies revealed by detwinned ARPES measurements of FeSe. https://doi.org/10.1088/1367-2630%2Faa8a04

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