The Multifaceted Physics of Correlated Topological Kagome Metals in Thin Films

Sunxiang Huang, University of Miami

August 17, 2021

Recently, a class of materials known as topological kagome metals (TKMs) are rapidly being recognized as exciting topological materials with embedded magnetic ordering and electron correlations. At the heart of TKMs are layered 2D kagome lattices occupied by transition metals (Fe, Mn, Co), which give rise to exotic topological band structure with a coexistence of Weyl/Dirac cones and flat bands. The research on TKMs has mostly centered on bulk compounds. The introduction of high-quality epitaxial films and heterostructures enables opportunities to achieve properties and functions impossible within parent materials.

In this talk, I will describe our realization of high-quality epitaxial thin films of several TKMs (Mn3Sn, Fe3Sn2, FeSn, and CoSn). I’ll then discuss their multifaceted physics in thin films, including Kondo physics in Mn3+xSn1-x [1], spintronic properties of TKMs [2,3], and superconducting proximity effect with potential triplet pairing in the heterostructure between TKMs and the superconductor Nb.

[1] D. Khadka, T. R. Thapaliya, S. H. Parra, X. Han, J. Wen, R. F. Need, P. Khanal, W. Wang, J. Zang, J. M. Kikkawa, L. Wu, and S. X. Huang. Kondo physics in antiferromagnetic Weyl semimetal Mn3+xSn1-x films. Science Advances 6, eabc1977 (2020).
[2] D. Khadka, T. R. Thapaliya, S. H. Parra, J. Wen, R. Need, J. M. Kikkawa, and S. X. Huang. Anomalous Hall and Nernst effects in epitaxial films of topological kagome magnet Fe
3Sn2. Physical Review Materials 4, 084203 (2020).
[3] D. Khadka, T. R. Thapaliya, J. Wen, R. F. Need, and S. X. Huang. High quality epitaxial thin films and exchange bias of antiferromagnetic Dirac semimetal FeSn. Applied Physics Letters 117, 032403 (2020).