Quantum oscillations of magnetoresistance in HgCdTe/HgTe/HgCdTe heterostructures with inverted band spectrum

The effects observed in the Shubnikov–de Haas oscillation regime in the HgCdTe/HgTe/HgCdTe heterostructure with a wide (20.3 nm) HgTe quantum well with an inverted band structure are discussed. In a topologically trivial 2D system, Pi(Greek letter) – shift of magnetooscillation phase is found. A thorough experimental study and theoretical analysis of the data is presented to understand the physical causes of this anomalous phase shift. The value of the effective electron mass $m_c/m_0$ = (0.022$\pm$0.002), obtained from the region of doubly degenerate peaks of magnetoresistance, is approximately half the theoretical estimates. In the region of stronger magnetic fields for nondegenerate peaks of magnetoresistance, we have $m_c/m_0$ = (0.034$\pm$0.003), which is in good agreement with both theoretical predictions and experimental results obtained from the analysis of activation conductivity in the quantum Hall effect regime. The reasons for this discrepancy are discussed.