Crossover from weak antilocalization to weak localization behavior in Bi2Te3/MnTe bilayer films

Electron–electron interactions (EEIs), quantum interference, and the effects of disorder on transport properties are essential topics in condensed matter physics. A series of our characterization work demonstrates that the morphology of Bi₂Te₃/MnTe bilayer film mainly depends on the magnetic substrate's growth mode and thickness. We propose that the temperature-dependent quantum interference of the electron wave function caused by disorder drives the transition from weak antilocalization (WAL) to weak localization (WL). Due to spin regulation, WL under low fields originates from the ferromagnetism in MnTe. The quantum interference effect (QIE) model analysis gives the degree of impurity scattering of the electron wave function. The electron wave is scattered by impurities, which causes the Berry phase to change from π to 0, producing a complete WL behavior. The stacked structure provides tunable degrees of freedom, allowing for independent optimization of topological properties and magnetic order through preferential growth orientation of topological insulator (TI) and magnetic layers, respectively.

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