Finite size effects on the quantum spin Hall state in HgTe quantum wells under two different types of boundary conditions*
Cheng Zhi, Chen Rui, Zhou Bin†
       
Energy spectra of the HgTe QW with an asymmetric geometry with one side of the TI strip being a TI/NI interface, and other side being a vacuum/TI interface (Fig.  1(b) ). Here the strengths R and Δ are assumed to be zero, the width L of the TI region is 1000 nm, and the width W of the NI region is 100 nm.