arXiv subjects

O. V. Kibis

Publications and source records attributed to O. V. Kibis.

At least 55 records · Page 3Linked to original sources

arXiv2017

Resonance fluorescence from an asymmetric quantum dot dressed by a bichromatic electromagnetic field

We present the theory of resonance fluorescence from an asymmetric quantum dot driven by a two-component electromagnetic field with two different frequencies, polarizations and amplitudes (bichromatic field) in the regime of strong light-matter coupling. It follows from the elaborated theory that the broken inversion symmetry of the driven quantum system and the bichromatic structure of the driving field result in unexpected features of the resonance fluorescence, including the infinite set of Mollow triplets, the quench of fluorescence peaks induced by the dressing field, and the oscillating behavior of the fluorescence intensity as a function of the dressing field amplitude. These quantum phenomena are of general physical nature and, therefore, can take place in various double-driven quantum systems with broken inversion symmetry.

cond-mat.mes-hall↗

arXiv2016

Optically tunable spin transport on the surface of a topological insulator

The emerging field of spinoptronics has a potential to supersede the functionality of modern electronics, while a proper description of strong light-matter coupling pose the most intriguing questions from both fundamental scientific and technological perspectives. In this paper we address a highly relevant issue for such a development. We theoretically explore spin dynamics on the surface of a 3D topological insulator (TI) irradiated with an off-resonant high-frequency electromagnetic wave. The strong coupling between electrons and the electromagnetic wave drastically modifies the spin properties of TI. The effects of irradiation are shown to result in anisotropy of electron energy spectrum near the Dirac point and suppression of spin current and are investigated in detail in this work.

cond-mat.mes-hall↗

arXiv2016

Effect of magnetic field on intersubband polaritons in a quantum well: Strong to weak coupling conversion

We investigate theoretically the effect of a magnetic field on intersubband polaritons in an asymmetric quantum well placed inside an optical resonator. It is demonstrated that the field-induced diamagnetic shift of electron subbands in the well increases the broadening of optical lines corresponding to intersubband electron transitions. As a consequence, the magnetic field can switch the polariton system from the regime of strong light-matter coupling to the regime of weak one. This effect paves a way to the effective control of polaritonic devices with a magnetic field.

cond-mat.mes-hall↗

arXiv2016

Magnetic properties of a two-dimensional electron gas strongly coupled to light

Considering the quantum dynamics of 2DEG exposed to both a stationary magnetic field and an intense high-frequency electromagnetic wave, we found that the wave decreases the scattering-induced broadening of Landau levels. Therefore, various magnetoelectronic properties of two-dimensional nanostructures (density of electronic states at Landau levels, magnetotransport, etc) are sensitive to the irradiation by light. Thus, the elaborated theory paves a way to optical controlling magnetic properties of 2DEG.

cond-mat.mes-hall↗

arXiv2016

Datta-and-Das spin transistor controlled by a high-frequency electromagnetic field

We developed the theory of spin dependent transport through a spin-modulator device (so-called Datta-and-Das spin transistor) in the presence of a high-frequency electromagnetic field (dressing field). Solving the Schrödinger problem for dressed electrons, we demonstrated that the field drastically modifies the spin transport. In particular, the dressing field leads to renormalization of spin-orbit coupling constants that varies conductivity of the spin transistor. The present effect paves the way for controlling the spin-polarized electron transport with light in prospective spin-optronic devices.

cond-mat.mes-hall↗

arXiv2016

Magnetoelectronic properties of graphene dressed by a high-frequency field

We solved the Schrödinger problem for electrons in graphene subjected to both a stationary magnetic field and a strong high-frequency electromagnetic wave (dressing field). The found solutions of the problem are used to describe the magnetoelectronic properties of dressed graphene. It follows from the present analysis that both optical characteristics and electronic transport are very sensitive to the dressing field. Particularly, the field strongly changes the spectra of optical absorption and the Shubnikov-de Haas oscillations. As a result, the developed theory opens a way for controlling magnetoelectronic properties of graphene with light.

cond-mat.mes-hall↗

arXiv2016

Optically controlled periodical chain of quantum rings

We demonstrated theoretically that a circularly polarized electromagnetic field substantially modifies electronic properties of a periodical chain of quantum rings. Particularly, the field opens band gaps in the electron energy spectrum of the chain, generates edge electron currents and induces the Fano-like features in the electron transport through the finite chain. These effects create physical prerequisites for the development of optically controlled nanodevices based on a set of coupled quantum rings.

cond-mat.mes-hall↗

arXiv2016

Control of electronic transport in graphene by electromagnetic dressing

We demonstrated theoretically that the renormalization of the electron energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field. Namely, linear polarization results in an anisotropic gapless energy spectrum, whereas circular polarization leads to an isotropic gapped one. As a consequence, the stationary (dc) electronic transport in graphene strongly depends on parameters of the dressing field: A circularly polarized field monotonically decreases the isotropic conductivity of graphene, whereas a linearly polarized one results in both giant anisotropy of conductivity (which can reach thousands of percents) and the oscillating behavior of the conductivity as a function of the field intensity. Since the predicted phenomena can be observed in a graphene layer irradiated by a monochromatic electromagnetic wave, the elaborated theory opens a substantially new way to control electronic properties of graphene with light.

cond-mat.mes-hall↗

arXiv2015

Control of spin dynamics in a two-dimensional electron gas by electromagnetic dressing

We solved the Schrödinger problem for a two-dimensional electron gas (2DEG) with the Rashba spin-orbit interaction in the presence of a strong high-frequency electromagnetic field (dressing field). The found eigenfunctions and eigenenergies of the problem are used to describe the spin dynamics of the dressed 2DEG within the formalism of the density matrix response function. Solving the equations of spin dynamics, we show that the dressing field can switch the spin relaxation in the 2DEG between the cases corresponding to the known Elliott-Yafet and D'yakonov-Perel' regimes. As a result, the spin properties of the 2DEG can be tuned by a high-frequency electromagnetic field. The present effect opens an unexplored way for controlling the spin with light and, therefore, forms the physical prerequisites for creating light-tuned spintronics devices.

cond-mat.mes-hall↗

arXiv2015

Collapse of electron band gaps in periodical structures dressed by a high-frequency field

It is demonstrated theoretically that the strong interaction between electrons in periodical structures and a high-frequency electromagnetic field suppresses the Bragg reflection of the electrons. As a result, the band gaps in electron energy spectra of the structures (the Bragg gaps) are collapsed. This quantum phenomenon can take place in various periodical structures, including both natural crystalline solids and artificial superlattices.

cond-mat.mes-hall↗

arXiv2015

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.

cond-mat.mes-hall↗

arXiv2015

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.

cond-mat.mes-hall↗

arXiv2015

Transport properties of a two-dimensional electron gas dressed by light

We show theoretically that the strong interaction of a two-dimensional electron gas (2DEG) with a dressing electromagnetic field drastically changes its transport properties. Particularly, the dressing field leads to the giant increase of conductivity (which can reach thousands of percents), results in nontrivial oscillating dependence of conductivity on the field intensity, and suppresses the weak localization of 2DEG. As a consequence, the developed theory opens an unexplored way to control transport properties of 2DEG by a strong high-frequency electromagnetic field. From experimental viewpoint, this theory is applicable directly to quantum wells exposed to a laser-generated electromagnetic wave.

cond-mat.mes-hall↗

arXiv2014

Optically induced Aharonov-Bohm effect in mesoscopic rings

We show theoretically that strong electron coupling to circularly polarized photons in non-singly-connected nanostructures results in the appearance of an artificial gauge field that changes the electron phase. The effect arises from the breaking of time-reversal symmetry and is analogous to the well-known Aharonov-Bohm phase effect. It can manifest itself in the oscillations of conductance as a function of the intensity and frequency of the illumination. The theory of the effect is elaborated for mesoscopic rings in both ballistic and diffusive regimes.

cond-mat.mes-hall↗

arXiv2014

Band gaps induced by vacuum photons in closed semiconductor cavities

We consider theoretically a closed (zero-dimensional) semiconductor microcavity where confined vacuum photonic mode is coupled to electrons in valence band of the semiconductor. It is shown that vacuum-induced virtual electron transitions between valence and conduction bands result in renormalization of electron energy spectrum. As a consequence, vacuum-induced band gaps appear within the valence band. Calculated values of the band gaps are of sub-meV scale, that makes this QED effect to be measurable in state-of-the-art experiments.

cond-mat.mes-hall↗

arXiv2014

Multiphoton interaction of a qutrit with single-mode quantized field in the ultrastrong and deep strong coupling regimes

We consider multiphoton dynamics of a quantum system composed of a three-state atom (a qutrit) and a single-mode photonic field in the ultrastrong and deep strong coupling regimes, when the coupling strength is comparable to or larger than the oscillator energy scale. We assume a qutrit to be in a polar-$Λ$ configuration in which two lower levels have mean dipole moments. Direct multiphoton resonant transitions revealing generalized Rabi oscillations, collapse, and revivals in atomic excitation probabilities for the ultrastrong couplings are studied. In the deep strong coupling regime particular emphasis is placed on the ground state of considering system which exhibits strictly nonclassical properties.

quant-ph↗

arXiv2014

Semiconductor cavity QED: Bandgap induced by vacuum fluctuations

We consider theoretically a semiconductor nanostructure embedded in one-dimensional microcavity and study the modification of its electron energy spectrum by the vacuum fluctuations of the electromagnetic field. To solve the problem, a non-perturbative diagrammatic approach based on the Green's function formalism is developed. It is shown that the interaction of the system with the vacuum fluctuations of the optical cavity opens gaps within the valence band of the semiconductor. The approach is verified for the case of large photon occupation numbers, proving the validity of the model by comparing to previous studies of the semiconductor system excited by a classical electromagnetic field. The developed theory is of general character and allows for unification of quantum and classical descriptions of the strong light-matter interaction in semiconductor structures.

cond-mat.mes-hall↗

arXiv2013

Persistent current induced by vacuum fluctuations in a quantum ring

We study theoretically interaction between electrons in a quantum ring embedded in a microcavity and vacuum fluctuations of electromagnetic field in the cavity. It is shown that the vacuum fluctuations can split electron states of the ring with opposite angular momenta. As a consequence, the ground state of electron system in the quantum ring can be associated to nonzero electric current. Since a ground-state current flows without dissipation, such a quantum ring gets a magnetic moment and can be treated as an artificial spin.

cond-mat.mes-hall↗