Temperature dependence of the resistance of a two-dimensional topological insulator in a HgTe quantum well

We report resistance measurements in HgTe wells with an inverted band structure near the charge neutrality point (CNP), where the system is expected to be a two-dimensional topological insulator with a dominant edge states contribution. The sample resistance is found to be about 100 times higher than the resistance quantum $h/2{e}^{2}$. Surprisingly, instead of a strong temperature dependence expected in such a seemingly insulating state the resistance at the CNP is found to be temperature independent at low temperatures. The experimental results are compared to the recent theoretical models.