Nonreciprocal charge transport in topological superconductor candidate Bi2Te3/PdTe2 heterostructure
Makoto Masuko, Minoru Kawamura, Ryutaro Yoshimi, Motoaki Hirayama, Yuya Ikeda, Ryota Watanabe, James Jun He, D. Maryenko, Atsushi Tsukazaki, Kei Takahashi, M. Kawasaki, Naoto Nagaosa, Yoshinori Tokura
Abstract
Abstract In a hybrid system of topological insulator (TI)/superconductor (SC), the proximity-induced topological superconductivity is expected to appear at the interface. Here we propose and demonstrate that a TI/SC hybrid Bi 2 Te 3 /PdTe 2 heterostructure serves as a platform for exploring topological superconductivity with various features: all made of tellurium compounds, epitaxial growth, and a small charge transfer interface. In the Bi 2 Te 3 /PdTe 2 heterostructure films, we observe large nonreciprocal charge transport near the superconducting transition temperature under a transverse in-plane magnetic field. The observation indicates the interplay between the topological surface state and superconductivity, suggesting that the Bi 2 Te 3 /PdTe 2 heterostructure is a candidate for a topological superconductor. Also observed is an unexpected sign reversal of the nonreciprocal coefficient when the in-plane magnetic field is slightly tilted toward the out-of-plane direction. The analysis reveals that the sign reversal occurs with the change of dominant vortex type, that is, the change from spontaneous vortices to external-field induced ones.