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TT: Fachverband Tiefe Temperaturen
TT 45: PtBi2 and Weyl Superconductors
TT 45.7: Vortrag
Mittwoch, 20. März 2024, 13:00–13:15, H 3010
Chiral Meissner state in time-reversal invariant Weyl superconductors — •Vira Shyta1, Jeroen van den Brink1,2, and Flavio S. Nogueira1 — 1Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany — 2Institute for Theoretical Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, TU Dresden, 01069 Dresden, Germany
Weyl semimetals have nodes in their electronic structure at which electrons attain a definite chirality. Due to the chiral anomaly, the non-conservation of charges with given chirality, the axion term appears in their effective electromagnetic action. We determine how this affects the properties of time-reversal invariant Weyl superconductors (SCs) in the London regime. For type II SCs the axion coupling generates magnetic B-fields transverse to vortices, which become unstable at a critical coupling so that a transition into type I SC ensues. In this regime an applied B-field not only decays inside the SC within the London penetration depth, but the axion coupling generates an additional perpendicular field. Consequently, when penetrating into the bulk the B-field starts to steadily rotate away from the applied field. At a critical coupling the screening of the magnetic field breaks down. The novel chiral SC state that emerges has a periodically divergent susceptibility that separates onsets of chiral Meissner regimes. Thus the axion leaves very crisp experimentally accessible signatures in Weyl SCs.
Keywords: Meissner state; Topological superconductors; Weyl semimetals