Kramers nodal lines in intercalated TaS$_2$ superconductors
Abstract
Kramers degeneracy is one fundamental embodiment of the quantum mechanical nature of particles with half-integer spin under time reversal symmetry. Under the chiral and noncentrosymmetric achiral crystalline symmetries, Kramers degeneracy emerges respectively as topological quasiparticles of Weyl fermions and Kramers nodal lines (KNLs), anchoring the Berry phase-related physics of electrons. However, an experimental demonstration for ideal KNLs well isolated at the Fermi level is lacking. Here, we establish a class of noncentrosymmetric achiral intercalated transition metal dichalcogenide superconductors with large Ising-type spin-orbit coupling, represented by InTaS, to host an ideal KNL phase. We provide evidence from angle-resolved photoemission spectroscopy with spin resolution, angle-dependent quantum oscillation measurements, and ab-initio calculations. Our work not only provides a realistic platform for realizing and tuning KNLs in layered materials, but also paves the way for exploring the interplay between KNLs and superconductivity, as well as applications pertaining to spintronics, valleytronics, and nonlinear transport.
Keywords
Cite
@article{arxiv.2503.08570,
title = {Kramers nodal lines in intercalated TaS$_2$ superconductors},
author = {Yichen Zhang and Yuxiang Gao and Aki Pulkkinen and Xingyao Guo and Jianwei Huang and Yucheng Guo and Ziqin Yue and Ji Seop Oh and Alex Moon and Mohamed Oudah and Xue-Jian Gao and Alberto Marmodoro and Alexei Fedorov and Sung-Kwan Mo and Makoto Hashimoto and Donghui Lu and Anil Rajapitamahuni and Elio Vescovo and Junichiro Kono and Alannah M. Hallas and Robert J. Birgeneau and Luis Balicas and Ján Minár and Pavan Hosur and Kam Tuen Law and Emilia Morosan and Ming Yi},
journal= {arXiv preprint arXiv:2503.08570},
year = {2025}
}
Comments
40 pages, 5 figures. Supplementary information PDF included in TeX Source