Magnetic-field-induced topological phase transition in Fe-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>Bi</mml:mi><mml:mo>,</mml:mo><mml:mi>Sb</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:msub><mml:mi mathvariant="normal">e</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> heterostructures
Y. Satake, J. Shiogai, G. P. Mazur, S. Kimura, S. Awaji, K. Fujiwara, T. Nojima, K. Nomura, S. Souma, T. Sato, T. Dietl, A. Tsukazaki
Abstract
Although Bi${}_{2}$Se${}_{3}$ is one of the most studied topological insulators, it has been difficult so far to observe the quantized anomalous Hall (QAH) effect due to the difficulty in the formation of a gapless chiral state in the gap formed by hybridization of surface states. The authors have developed the molecular beam epitaxial growth of paramagnetic Fe-doped Bi${}_{2}$Se${}_{3}$-based heterostructures with well-controlled thickness and Bi/Sb composition ratio. The application of a magnetic field resulted in the emergence of QAH conductance driven by a giant exchange splitting of topological states. The demonstration of finely tuned architectures of topological materials will accelerate in-depth understanding of the topological phase transitions.