Localization and interference induced quantum effects at low magnetic fields in InGaAs/GaAs structures
A. P. Savelyev, Yu. G. Arapov, S. V. Gudina, V. N. Neverov, S. M. Podgornykh, N. G. Shelushinina, and M. V. Yakunin
M.N. Miheev Institute of Metal Physics of the Ural Branch of the Russian Academy of SciencesEkaterinburg 620108, Russia
Received September 29, 2020, published online November 24, 2020
The longitudinal ρxx(B, T) and Hall ρxy(B, T) resistances are experimentally investigated in n-InGaAs/GaAs nanostructures with a single and double quantum wells in the magnetic field range B = 0–2.5 T and temperatures T = 1.8–20 K. It is shown that the origin of the temperature-independent point located at ωcτ ≅ 1 on the ρxx(B, T) curves is due to the combined action of the classical cyclotron motion and the quantum interference effects of weak localization and electron-electron interaction. The results obtained indicate that the transition from the dielectric phase to the phase of the quantum Hall effect is a crossover from weak localization (quantum interference effects in a weak magnetic field) to strong localization in quantizing magnetic fields in the quantum Hall effect regime.
Key words: quantum Hall effect, crossover, quantum interference.