Abstract
Topological superconductivity in multiband systems has received much attention due to a variety of possible exotic superconducting order parameters as well as non-trivial bulk and surface states. While the impact of coexisting magnetic order on superconductivity has been studied for many years, such as ferromagnetic superconductors, the implication of coexisting multipolar order has not been explored much despite the possibility of multipolar hidden order in a number of $f$-electron materials. In this work, we investigate topological properties of multipolar superconductors that may arise when quadrupolar local moments are coupled to conduction electrons in the multiband Luttinger semimetal. We show that the multipolar ordering of local moments leads to various multipolar superconductors with distinct topological properties. We apply these results to the quadrupolar Kondo semimetal system, PrBi, by deriving the microscopic multipolar Kondo model and examining the possible superconducting order parameters. We also discuss how to experimentally probe the topological nature of the Bogoliubov quasiparticles in distinct multipolar superconductors via doping and external pressure, especially in the context of PrBi.
Highlights
One of the foremost themes in contemporary condensedmatter physics is the realization of topological superconductivity, where Bogoliubov–de Gennes (BdG) quasiparticles are characterized by nontrivial topology [1,2,3,4]
We have studied exotic multipolar superconductors and their topological properties, which arise from the intertwined multipolar order and electron correlations in the Luttinger semimetal
Based on the derivation of microscopic modeling of Kondo coupling between quadrupolar moments and conduction electrons, we found that the onset of ferroquadrupolar order affects the Fermi-surface distortion, and thereby multipolar superconductors occur in preferred d-wave superconducting order parameters
Summary
One of the foremost themes in contemporary condensedmatter physics is the realization of topological superconductivity, where Bogoliubov–de Gennes (BdG) quasiparticles are characterized by nontrivial topology [1,2,3,4]. It has been shown that the electron-electron interaction favors the d-wave pairing channels in the j = 2 manifold over the s wave in the j = 0 state [19] Such unconventional superconductors possess a number of striking features, including the emergent topological boundary states and the Bogoliubov Fermi surfaces with nontrivial Chern numbers [13,14,15,38]. The pyrochlore oxide Cd2Re2O7 and Pr-based intermetallic compounds Pr(T )2X20 (T =Ti, V, Rh, Ir and X =Al, Zn) were recently found to show the coexistence of multipolar order and superconductivity [46,47,48,49,50,51,52,53,54,55,56,57] Another semimetallic system, PrBi, is known to have both the quadrupolar degrees of freedom coming from Pr ions and the j = 3/2 Luttinger semimetal. We propose various experiments that can probe the topological nature of the Bogoliubov quasiparticles in multipolar superconductors, anticipating potential applications to PrBi materials with doping and external pressure
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
