Magnetization amplification in the interlayer pairing superconductor 4Hb-TaS${}_2$

Abstract

A recent experiment on the bulk compound 4Hb-TaS${}_2$ reveals an unusual time-reversal symmetry-breaking superconducting state that possesses a magnetic memory not manifest in the normal state. Here we provide a mechanism for this observation by studying the magnetic and electronic properties of 4Hb-TaS${}_2$. We discuss the criterion for a small magnetization in the normal state in terms of spin and orbital magnetizations. Based on an analysis of lattice symmetry and Fermi surface structure, we propose that 4Hb-TaS${}_2$ realizes superconductivity in the interlayer, equal-spin channel with a gap function whose phase winds along the Fermi surface by an integer multiple of $6\pi$. The enhancement of the magnetization in the superconducting state compared to the normal state can be explained if the state with a gap winding of $6\pi$ is realized, accounting for the observed magnetic memory. We discuss how this superconducting state can be probed experimentally by spin-polarized scanning tunneling microscopy.

19 pages; published version

References in corpus (11)

• Three-band tight-binding model for monolayers of group-VIB transition metal dichalcogenides
• Orbital magnetization in crystalline solids: Multi-band insulators, Chern insulators, and metals
• Quantum Theory of Orbital Magnetization and its Generalization to Interacting Systems
• Visualization of Topological Boundary Modes Manifesting Topological Nodal-Point Superconductivity
• Superconductivity and Local Inversion-Symmetry Breaking
• Spin-polarized Yu-Shiba-Rusinov states in an iron based superconductor
• Robust parity-mixed superconductivity in disordered monolayer transition metal dichalcogenides
• Robust Gapless Superconductivity in 4Hb-TaS${}_2$
• Theory of Multi-Orbital Topological Superconductivity in Transition Metal Dichalcogenides
• Modern Theory for the Orbital Moment in a Superconductor
• Kondo enabled transmutation between spinons and superconducting vortices: origin of magnetic memory in 4Hb-$\mathrm{Ta}{\mathrm{S}}_2$

Cited by in corpus (1)

• Anomalous currents and spontaneous vortices in spin-orbit coupled superconductors