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arXiv · 2307.10389

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

Chunxiao Liu·Shubhayu Chatterjee·Thomas Scaffidi·Erez Berg·Ehud Altman
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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.

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Chunxiao Liu, Shubhayu Chatterjee, Thomas Scaffidi, Erez Berg, Ehud Altman. 2023-07-19. Magnetization amplification in the interlayer pairing superconductor 4Hb-TaS$_2$. https://doi.org/10.1103/physrevb.110.024502

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