Controlling the Superconducting Transition by Rotation of an Inversion Symmetry-Breaking Axis

Abstract

We consider a hybrid structure where a material with Rashba-like spin-orbit coupling is proximity coupled to a conventional superconductor. We find that the superconducting critical temperature T c can be tuned by rotating the vector n characterizing the axis of broken inversion symmetry. This is explained by a leakage of s-wave singlet Cooper pairs out of the superconducting region, and by conversion of s-wave singlets into other types of correlations, among these s-wave odd-frequency pairs robust to impurity scattering. These results demonstrate a conceptually different way of tuning T c compared to the previously studied variation of T c in magnetic hybrids.

Interfacial control of vortex-limited critical current in type II superconductor films

“…On the theory side, the vortex surface barriers and corresponding critical currents should be evaluated numerically for various superconducting hybrids of interest [27,78,79], for example using the quasiclassical Green's function method [80] or Bogoliubov-de Gennes equation [1]. The recent new insights regarding orbital contributions to magnetization in superconductors with Rashba SOC [81] pose another important question and could offer an avenue for enhancement of the critical current modulation.…”

Magnetic control of superconducting heterostructures using compensated antiferromagnets

“…Our binomial search algorithm for the superconducting critical temperature, is the same as the one we have previously presented in Ref. [18], and we only summarize the main steps here. We divide the temperature interval 𝑁 𝑇 times.…”

“…Previous studies have suggested introducing heavy-metal layers boosting the interfacial Rashba spin-orbit coupling in a S/F bilayer [11][12][13][14][15][16][17]. The Rashba spin-orbit field introduces additional symmetry breaking [18] that allows for control over the spin-triplet channels when rotating the magnetization of the single ferromagnetic layer. However, for a structure with purely Rashba spin-orbit coupling, a variation in the triplet generation for in-plane rotations of the magnetization is only possible in ballistic-limit systems [15], while additional Dresselhaus spin-orbit coupling is needed for such an in-plane effect in the diffusive limit [11].…”

Controllable Enhancement of p -Wave Superconductivity via Magnetic Coupling to a Conventional Superconductor

“…In this setup, the interface normal is parallel to the x axis, meaning spatial inversion symmetry is broken along x. The SF bilayer converts even-frequency s-wave singlets into evenfrequency p x -wave triplets and odd-frequency s-wave triplets [56]. The latter do not contribute to the T c enhancement discussed here.…”