Topological phase transitions by interface engineering

Novel phase transitions, espacially topological phase transitions, have attracted intense interests in condensed mattered physics in recent years. However, the reported materials possess novel phases are majorly composed of heavy elements with relatively low abundances. We switched investigate objectives into commonly-used semiconductors, and demonstrated that, utilizing giant electric fields generated by charge accumulation at GaAs/Ge/GaAs opposite semiconductor interfaces and band folding, the interface engineering can reduce the sizable gap in Ge, induce large spin-orbit interaction, and drive Ge into a topological insulating phase [1]. Natural topological semimetals hosting multiple topological states will be demonstrated through simple symmetry considerations [2,3], and the possibilities to realize “ideal” topological semimetals utilizing interface design[4] will also be disscussed.
References
[1]. Dong Zhang, Wenkai Lou, Maosheng Miao, Shou-cheng Zhang, and Kai Chang, Phys. Rev. Lett. 111, 156402 (2013).
[2]. JP Sun, D Zhang, K Chang Chinese Physics Letters 34, 027102 (2017) (Express Lett.)
[3]. JP Sun, D Zhang, K Chang Physical Review B 96, 045121 (2017)
[4]. JP Sun, J Zhu, D Zhang, K Chang arXiv:1607.04391