Shot noise of the edge transport in the inverted band HgTe quantum wells
E. S. Tikhonov+*, D. V. Shovkun+*, V. S. Khrapai+*, Z. D. Kvon×°, N. N. Mikhailov∇, S. A. Dvoretsky∇
+Institute of Solid State Physics of the RAS, 142432 Chernogolovka, Russia
*Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
×Rzhanov Institute of Semiconductor Physics SB of the RAS, 630090 Novosibirsk, Russia
°Novosibirsk State University, 630090 Novosibirsk, Russia
∇Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
Abstract
We investigate the current noise in HgTe-based quantum wells with an inverted
band structure in the regime of disordered edge transport.
Consistent with previous experiments, the edge resistance strongly exceeds
h/e2 and weakly depends on the temperature. The shot noise is well below
the Poissonian value and characterized by the Fano factor with gate voltage
and sample to sample variations in the range 0.1<F<0.3. Given the fact that
our devices are shorter than the most pessimistic estimate of the ballistic
dephasing length, these observations exclude the possibility of
one-dimensional helical edge transport. Instead, we suggest that a disordered
multi-mode conduction is responsible for the edge transport in our
experiment.