Abstract
We present a theory of the high-spin generalization of topological insulators and their doped superconducting states. The higher-spin topological insulators involve a pair of $J=3/2$ bands with opposite parity, and are characterized by their band inversion. The low-energy effective theory reveals that the topological insulators host four different phases characterized by mirror Chern numbers, at which boundaries two different patterns of bulk Dirac points appear. For the carrier-doped case, it is shown that the system may host unique unconventional superconductivity because of its high-spin nature and additional orbital degrees of freedom intrinsic to topological insulators. The superconducting critical temperature is evaluated by using density-density pairing interactions, and odd-parity Cooper pairs are shown to be naturally realized in the presence of interorbital pairing interaction. It is observed that even the simplest spin 0 odd-parity pairing state exhibits a novel class of topological superconductivity---high winding topological superconductivity. We also discuss the experimental signals of high winding topological superconductivity in the case of the antiperovskite superconductor Sr$_{3-x}$SnO.
Highlights
The search for topological materials is a recent trend in condensed matter physics [1,2,3,4,5,6,7,8]
We reveal that the simplest J 1⁄4 0 odd-parity pairing state shows a new class of topological superconductivity, i.e., high winding topological superconductivity
We have investigated topological superconductivity in doped topological insulators (TIs) of J 1⁄4 3=2 electrons
Summary
The search for topological materials is a recent trend in condensed matter physics [1,2,3,4,5,6,7,8]. It has been recognized that multiorbital systems may solve this difficulty, as they allow another mechanism of topological superconductivity [8]: Using interorbital pairing interaction and spin-orbit coupling, a multiorbital system may host odd-parity Cooper pairs even without a strong correlation [18], which indicates topological superconductivity [17,18,19] In this new direction, various types of topological superconductivity in doped topological materials have been discussed recently [18,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.