The temperature dependence of anomalous magnetoresistance and weak antilocalization in HgTe/CdTe (111) quantum wells

摘要

The temperature dependence of anomalous magnetoresistance and weak antilocalization (WAL) is studied in HgTe/CdTe (111) quantum wells (QWs). An anomalous positive to negative magnetoresistance transformation dependent on temperature is observed in HgTe/CdTe QWs grown at 157°C, but not in those grown at 160 °C. The Hikami-Larkin-Nagaoka model is employed to analyze the WAL effect. A high-resolution transmission electron microscopy investigation of the HgTe-CdTe interface supports the transport results. For HgTe topologi-cal insulators, the anomalous magnetoresistance may be caused by temperature-induced fluctuations in conduction, which could transform the inverted energy band to a normal energy band. At high temperature, the negative magnetoresistance may be due to scattering of the interface defective states under the normal energy band.