Real Space Imaging Of Topological Edge States In Inas/Gasb And Inas/Inxga1-Xsb Quantum Wells

Structure dependent differential tunneling conductance, dI/dV, profiles obtained using scanning tunneling microscopy on both (110) -cleaved surfaces and (001) -growth surfaces in InAs/GaSb and InAs/InxGa1-xSb quantum wells (QWs), which are platforms of twodimensional topological insulator (2D-TI), clearly demonstrated the edge states formed on the 2D-TI surfaces. The results were confirmed by kp-based electronic structure calculations, which demonstrated that the edge states extended to the 10 nm range from cleaved surfaces generated in the appropriately designed InAs/(In)GaSb QW systems.