Quantum anomalous Hall interferometer

Electronic interferometries in integer and fractional quantum Hall regimes have unfolded the coherence, correlation, and statistical properties of interfering constituents. This is addressed by investigating the roles played by the Aharonov-Bohm effect and Coulomb interactions on the oscillations of transmission/reflection. Here, we construct magnetic interferometers using Cr-doped (Bi,Sb)(2)Te-3 films and demonstrate the electronic interferometry using chiral edge states in the quantum anomalous Hall regime. By controlling the extent of edge coupling and the amount of threading magnetic flux, distinct interfering patterns were observed, which highlight the interplay between the Coulomb interactions and Aharonov-Bohm interference by edge states. The observed interference is likely to exhibit a long-range coherence and robustness against thermal smearing probably owing to the long-range magnetic order. Our interferometer establishes a platform for (quasi)particle interference and topological qubits.

Automated summary

By investigating the roles played by the Aharonov-Bohm effect and Coulomb interactions, we successfully constructed magnetic interferometers using Cr-doped (Bi,Sb)(2)Te-3 films and demonstrated electronic interferometry using chiral edge states in the quantum anomalous Hall regime. The observed interference patterns highlight the interplay between Coulomb interactions and Aharonov-Bohm interference by edge states. The long-range coherence and robustness against thermal smearing exhibited by the observed interference are likely due to the long-range magnetic order. Our interferometer provides a platform for (quasi)particle interference and topological qubits.