Aharonov-Bohm interferometer on helical edge states: Coherent enhancement of scattering off magnetic impurity
The wave nature of electrons is manifested in a quantum-coherent phenomenon - interference. This phenomenon is the foundation of devices, named interferometers, which is used for high-sensitivity measurement of the magnetic field, electron spin control and for quantum computation. We discuss the transport of electrons through the Aharonov-Bohm interferometer [1] which is created on the helical edge states connected to metallic leads. The dependence of the electron transport on the magnetic flux piercing the area encompassed by edge states is studied. We consider the case of relatively high temperatures as compared to the distance between the energy levels of the system [2]. It is shown [3] that the tunnel conductance of the interferometer does not depend on the magnetic flux in the ballistic case. Nevertheless, it has a sharp resonance as a function of the magnetic flux in the presence of a magnetic impurity. This resonance behavior can be related to the coherent enhancement of forward and back scattering by a magnetic impurity - a very similar effect to the phenomenon of weak localization.
[1] A. G. Aronov and Y. V. Sharvin, Rev. Mod. Phys. 59 (1987) 755.
[2] A.P. Dmitriev, I.V. Gornyi, V.Y. Kachorovskii, D.G. Polyakov, Phys. Rev. Lett., 105 (2010) 036402.
[3] R.A. Niyazov, D.N. Aristov, V.Yu. Kachorovskii, arXiv:1804.01115.