Dissipationless electron transport in photon-dressed nanostructures

It is shown that the electron coupling to photons in field-dressed nanostructures can result in the ground electron-photon state with a nonzero electric current. Since the current is associated with the ground state, it flows without the Joule heating of the nanostructure and is nondissipative. Such a dissipationless electron transport can be realized in strongly coupled electron-photon systems with the broken time-reversal symmetry - particularly, in quantum rings and chiral nanostructures dressed by circularly polarized photons.Comment: 4 pages; 1 figure; published versio

How to suppress the backscattering of conduction electrons?

It is shown theoretically that the strong coupling of electrons to a high-frequency electromagnetic field results in the nulling of electron backscattering within the Born approximation. The conditions of the effect depend only on field parameters and do not depend on concrete form of scattering potential. As a consequence, this phenomenon is of universal physical nature and can take place in various conducting systems. Since the suppression of electron backscattering results in decreasing electrical resistance, the solved quantum-mechanical problem opens a new way to control electronic transport properties of conductors by a laser-generated field. Particularly, the elaborated theory is applicable to nanostructures exposed to a strong monochromatic electromagnetic wave.Comment: Published versio

Aharonov-Bohm effect for excitons in a semiconductor quantum ring dressed by circularly polarized light

We show theoretically that the strong coupling of circularly polarized photons to an exciton in ring-like semiconductor nanostructures results in physical nonequivalence of clockwise and counterclockwise exciton rotations in the ring. As a consequence, the stationary energy splitting of exciton states corresponding to these mutually opposite rotations appears. This excitonic Aharonov-Bohm effect depends on the intensity and frequency of the circularly polarized field and can be detected in state-of-the-art optical experiments.Comment: Published versio

Structure of surface electronic states in strained mercury telluride

We present the theory describing the various surface electronic states arisen from the mixing of conduction and valence bands in a strained mercury telluride (HgTe) bulk material. We demonstrate that the strain-induced band gap in the Brillouin zone center of HgTe results in the surface states of two different kinds. Surface states of the first kind exist in the small region of electron wave vectors near the center of the Brillouin zone and have the Dirac linear electron dispersion characteristic for topological states. The surface states of the second kind exist only far from the center of the Brillouin zone and have the parabolic dispersion for large wave vectors. The structure of these surface electronic states is studied both analytically and numerically in the broad range of their parameters, aiming to develop its systematic understanding for the relevant model Hamiltonian. The results bring attention to the rich surface physics relevant for topological systems.Comment: Published version. arXiv admin note: text overlap with arXiv:1903.0457