Towards Multiple Majorana Zero Modes in Pb_1-xSn_xTe/FeTe Heterostructures

Heterostructures formed by stacking a topological crystalline insulator (TCI) and an s-wave superconductor provide a promising route to realizing multiple Majorana zero modes (MZMs). In this work, we employed molecular beam epitaxy (MBE) to grow a series of Pb_1-xSn_xTe/FeTe heterostructures, where Pb_1-xSn_xTe exhibits a TCI phase within a specific x range. Unlike conventional topological insulators, TCIs host multiple Dirac cones in the first Brillouin zone. Angle-resolved photoemission spectroscopy (ARPES) measurements reveal a topological phase transition from a trivial semiconductor to a TCI as x increases. Electrical transport measurements show that robust interfaced-induced superconductivity emerges across all x with a critical temperature T_c ~ 12 K. The superconducting phase rigidity, probed by the double-coil mutual inductance measurements of the superfluid density, further confirms the robustness of the superconducting state. These results establish the coexistence of superconductivity and multiple Dirac cone structures in Pb_1-xSn_xTe/FeTe heterostructures, offering a platform for exploring multiple MZMs.