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Electric field modulation of topological order in thin film semiconductors
We propose a method that can consecutively modulate the topological orders or
the number of helical edge states in ultrathin film semiconductors without a
magnetic field. By applying a staggered periodic potential, the system
undergoes a transition from a topological trivial insulating state into a
non-trivial one with helical edge states emerging in the band gap. Further
study demonstrates that the number of helical edge state can be modulated by
the amplitude and the geometry of the electric potential in a step-wise
fashion, which is analogous to tuning the integer quantum Hall conductance by a
megntic field. We address the feasibility of experimental measurement of this
topological transition.Comment: 4 pages, 4 figure
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