Imaging currents in HgTe quantum wells in the quantum spin Hall regime

Understand

The quantum spin Hall (QSH) state is a genuinely new state of matter characterized by a non-trivial topology of its band structure.

• Its key feature is conducting edge channels whose spin polarization has potential for spintronic and quantum information applications.
• The QSH state was predicted and experimentally demonstrated to exist in HgTe quantum wells.
• The existence of the edge channels has been inferred from the fact that local and non-local conductance values in sufficiently small devices are close to the quantized values expected for ideal edge channels and from signatures of the spin polarization.