Topological Solitons in Three-Band Superconductors with Broken Time Reversal Symmetry

Abstract

We show that three-band superconductors with broken time reversal symmetry allow magnetic flux-carrying stable topological solitons. They can be induced by fluctuations or quenching the system through a phase transition. It can provide an experimental signature of the time reversal symmetry breakdown.

Vortices with Fractional Flux Quanta in Multi-Band Superconductors

“…The situation is different when a phase separation exists between the two time-reversal symmetry broken (TRSB) superconducting states with opposite chiralities in a sample. On domain walls 12,[24][25][26] , interband phase difference develops a phase kink as shown in Fig. 1, resulting in different winding numbers in different components in presence of external magnetic field.…”

Distinct magnetic signatures of fractional vortex configurations in multiband superconductors

“…12). In addition, dynamic dissociation of vortices is predicted in the flux flow regime [13], as well as the stationary vortex splitting [14,15] stemming from phase frustration in superconductors with three or more bands [16,17], but neither of those vortex fractionalizations has been realized to date.In this Letter we explore the effect of a surface in stabilizing the fractional vortices in multiband superconductors [18], and propose static (dc) and dynamic (ac) measurements to directly detect them. We consider a twoband superconducting slab in parallel magnetic field H, with width much larger than the field penetration depth in order to prevent strong confinement effects.…”

“…12). In addition, dynamic dissociation of vortices is predicted in the flux flow regime [13], as well as the stationary vortex splitting [14,15] stemming from phase frustration in superconductors with three or more bands [16,17], but neither of those vortex fractionalizations has been realized to date.…”

ChiralCP2skyrmions in three-band superconductors

“…There, the ground state explicitly breaks the discrete U(1) × Z 2 symmetry. 6,7 Related multicomponent states were also recently discussed, in connection with other materials. 8 If superconductivity in iron pnictides is described by just a two-band s ± models, BTRS states can nonetheless be obtained in a Josephson-coupled bilayer of s ± superconductor and ordinary s-wave material.…”

“…3,6,7,[9][10][11][12][13][14] These phenomena include: exotic collective modes which are different from the Leggett's mode; 7,10,15 the existence of a large disparity in coherence lengths even when intercomponent Josephson coupling is very strong, leading to type-1.5 regimes 7 (where some coherence lengths are smaller and some are larger than the magnetic field penetration length 16 ); the possibility of flux-carrying topological solitons different from Abrikosov vortices. 6 This paper is a follow-up to Ref. 6 where we introduced new flux-carrying topological solitons.…”