Superconducting proximity effect in inverted InAs/GaSb quantum well   structures with Ta electrodes
  We present our recent electronic transport results in top-gated InAs/GaSb quantum well hybrid structures with superconducting Ta electrodes. We show that the transport across the InAs-Ta junction depends largely on the interfacial transparency, exhibiting distinct zero-bias behavior. For a relatively resistive interface a broad conductance peak is observed at zero bias. When a transparent InAs-Ta interface is achieved, a zero-bias conductance dip appears with two coherent-peak-like features forming at bias voltages corresponding to the superconducting gap of Ta. The conductance spectra of the transparent InAs-Ta junction at different gate voltages can be fit well using the standard Blonder-Tinkham-Klapwijk theory. 
Wenlong Yu, Yuxuan Jiang, Chao Huan, Xunchi Chen, Zhigang Jiang,   Samuel D. Hawkins, John F. Klem, and Wei Pan
cond-mat.mes-hall