Weyl superconductor phases in a Weyl-semimetal/superconductor multilayer

Abstract

Topologically nontrivial superconducting phases have been engineered in topological materials by the proximity effect in contact with conventional superconductors. In this paper, by using the method of the Kronig-Penney model, we study the superconducting proximity effect in the bulk electronic states of Weyl semimetals by considering a multilayer structure consisting of Weyl-semimetal and superconductor layers. Due to the proximity effect, two Weyl nodes are decoupled into four nodes of Majorana fermions resulting in Weyl-superconductor phases or three-dimensional extension of topological-superconductor phases. We find that mismatch of the Fermi velocity and potential barriers at the interface gap out Majorana nodes, thus turn Weyl-superconductor phases with four Majorana nodes into Weyl-superconductor phases with half of Majorana nodes and topologicalsuperconductor phases with odd integer Chern numbers. CONTENTS

Resonant x-ray scattering study of diffuse magnetic scattering from the topological semimetals EuCd2As2 and EuCd2Sb2Soh1, Schierle2, Yan3 et al. 2020Phys. Rev. B25160View full textAdd to dashboardCite

“…1(b)]. This finding has stimulated investigations into various physical properties of EuCd 2 As 2 , including anomalous conductance scaling [29], topological magnetotorsional effect [30], Weylsuperconductor phase [31], quantum anomalous Hall effect [32], axial anomaly generation [33], and nonreciprocal thermal radiation [34]. The WSM state arises in EuCd 2 As 2 when the Eu moments are ferromagnetically (FM) aligned along the crystal c axis.…”

Comprehensive review on topological superconducting materials and interfaces

“…Apart from a topological insulator, there are several theoretical assumptions that topological superconductivity can be found at the interface of a topological semimetal (TSM) and a superconductor [294][295][296][297]. But on experimental grounds, there are very few reports which show topological superconductivity at the interface between a TSM and a superconductor.…”

Topological superconducting domain walls in magnetic Weyl semimetals

“…Magnetic Weyl semimetals are expected to host topological superconductivity when put in proximity to a trivial superconductor [11][12][13][14][15][16][17] . This delicate state is predicted to support chiral Majorana modes or localized Majorana bound states at edges, endings or defects [18][19][20] .…”