Bulk transport paths through defects in floating zone and Al flux grown SmB$_6$
Abstract
We investigate the roles of disorder on low-temperature transport in SmB crystals grown by both the Al flux and floating zone methods. We used the inverted resistance method with Corbino geometry to investigate whether low-temperature variations in the standard resistance plateau arises from a surface or a bulk channel in floating zone samples. The results show significant sample-dependent residual bulk conduction, in contrast to smaller amounts of residual bulk conduction previously observed in Al flux grown samples with Sm vacancies. We consider hopping in an activated impurity band as a possible source for the observed bulk conduction, but it is unlikely that the large residual bulk conduction seen in floating zone samples is solely due to Sm vacancies. We therefore propose that one-dimensional defects, or dislocations, contribute as well. Using chemical etching, we find evidence for dislocations in both flux and floating zone samples, with higher dislocation density in floating zone samples than in Al flux grown samples. In addition to the possibility of transport through one-dimensional dislocations, we also discuss our results in the context of recent theoretical models of SmB.
Cite
@article{arxiv.2011.08923,
title = {Bulk transport paths through defects in floating zone and Al flux grown SmB$_6$},
author = {Yun Suk Eo and Alexa Rakoski and Shriya Sinha and Dmitri Mihaliov and Wesley T. Fuhrman and Shanta R. Saha and Priscila F. S. Rosa and Zachary Fisk and Monica Ciomaga Hatnean and Geetha Balakrishnan and Juan R. Chamorro and Seyed M. Koohpayeh and Tyrel M. McQueen and Boyoun Kang and Myung-suk Song and Beongki Cho and Michael S. Fuhrer and Johnpierre Paglione and Cagliyan Kurdak},
journal= {arXiv preprint arXiv:2011.08923},
year = {2021}
}
Comments
22 pages, 4 figures