Electronic structure of the InSb-CdTe-αSn interface: using CdTe as a barrier*

Understanding the effects of interfacing materials is pivotal to the design of semiconductor, spintronic, and quantum devices. We study the InSb-CdTe-αSn interface via density functional theory (DFT).  

InSb is the backbone of Majorana devices for topological quantum computing and Sn is a superconductor that is utilized to supply the required superconductivity. CdTe is explored as a tunnel barrier between the InSb/αSn interface.

The PBE+U method is used, with the Hubbard U parameters found via a machine-learned Bayesian optimization algorithm, allowing the simulation of large interfaces. We discuss effects such as band offsets at the interfaces, metal induced gap states (MIGS) and the effects of varying the barrier thickness. 

We also study the comparison of our CdTe and αSn DFT data with experimental ARPES data, utilizing the tools of bulk and z-unfolding to visualize our data.