Switchable giant non-reciprocity under out-of-plane magnetic field in superconducting (Cr,Bi,Sb)2Te3 / PdTe2 heterostructures

The interplay between broken inversion symmetry, superconductivity and unconventional topological magnetism is expected to support tunable non-reciprocity, exotic Majorana phenomena and superconducting spintronics functionality. High-quality, transparent interfaces with the superconductor (SC) are crucial, but challenging to achieve to date. We report, for the first time, high-quality thin films of superconducting PdTe₂ grown epitaxially with (Cr,Bi,Sb)₂Te₃ [1]. Our heterostructure provides a platform where superconductivity can epitaxially proximitize the full zoo of phases available in the (Cr,Bi,Sb)₂Te₃ platform, including QAH states, semi-magnetic TIs and skyrmions [2-4]. In Bi₂Te₃ / PdTe₂ we observe giant non-reciprocal charge transport, several orders of magnitude larger than that reported in 2D polar SCs, indicating unexpected interplay between the topological surface state and superconductivity. We further observe a remarkable sign-reversal (switch) of the non-reciprocity when the magnetic field includes a small out-of-plane component, which we conclude arises from a crossover in the vortex type. Lastly, we discuss epitaxial superconducting proximity effects associated with other exotic topological phases in the (Cr,Bi,Sb)₂Te₃ platform, and comment on novel device functionality.



[1] Masuko et al., npj Quant. Mat. (2022).

[2] Tokura, Yasuda and Tsukazaki Nat. Rev. Phys. 1, 126 (2019).

[3] Mogi et al., Nat. Phys. 18, 390 (2022).

[4] Okazaki et al., Nat. Phys. 18, 25 (2022).