Local noncentrosymmetricity and possible spin-momentum locking in Sr$_3$Ru$_2$O$_7$
Abstract
Strong spin-orbital coupling (SOC) was found previously to lead to dramatic effects in quantum materials, such as those found in topological insulators. It was shown theoretically that local noncentrosymmetricity resulting from the rotation of RuO octahedral in SrRuO will also give rise to an effective SOC\cite{SocSr327,MicroscopicnematicSr327}. In the presence of a magnetic field applied along a specific in-plane direction, the Fermi surface was predicted to undergo a reconstruction. Here we report results of our in-plane magnetoresistivity and magnetothermopower measurements on single crystals of SrRuO with an electrical or a thermal current applied along specific crystalline directions and a magnetic field rotating in the plane (Fig. 1a), showing a minimal value for field directions predicted by the local noncentrosymmetricity theory. Furthermore, the thermopower, and therefore, the electron entropy, were found to be suppressed as the field was applied perpendicular to the thermal current, which suggests that the spin and the momentum in SrRuO are locked over substantial parts of the Fermi surface, likely originating from local noncentrosymmetricity as well.
Keywords
Cite
@article{arxiv.1507.00229,
title = {Local noncentrosymmetricity and possible spin-momentum locking in Sr$_3$Ru$_2$O$_7$},
author = {Chenyi Shen and Hui Xing and Xinxin Cai and David Fobes and Mingliang Tian and Zhi-Qiang Mao and Zhuan Xu and Ying Liu},
journal= {arXiv preprint arXiv:1507.00229},
year = {2015}
}