Theory of topological Kondo superconductors: an application to UTe₂

Yung-Yeh Chang^1*, Khoe Van Nguyen², Kuang-Lung Chen², Chung-Hou Chung²

¹Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
²Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

* Presenter:Yung-Yeh Chang, email:cdshjtr@gmail.com

Spin-triplet p-wave superconductors are promising candidates for topological superconductors. They have been proposed in various heterostructures where a strong spin-orbit interacting materials is coupled to a conventional s-wave superconductor by proximity effect. However, topological superconductors existing in nature and driven by strong electron correlations is yet to be studied. Here we propose the first realization of such system in a class of Kondo lattice materials without proximity effect. Therein, the odd-parity Kondo hybridization mediates ferromagnetic spin-spin coupling and leads to spin-triplet resonant-valence-bond (t-RVB) pairing between local moments. Spin-triplet p ± ip'-wave topological superconductivity is reached when Kondo effect co-exists with t-RVB. We identify the topological nature by the non-trivial topological invariant and the Majorana fermions at edges. Experimental implications of our results on the U-based ferromagnetic heavy-electron superconductors with Kondo correlations, in particular UTe₂, is discussed.

* This work is supported by the Ministry of Science and Technology and the National Center for Theoretical Sciences of Taiwan.

Keywords: Heavy fermion, Kondo effect, Majorana zero mode