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1.
We have studied CR lineshape of terahertz-light-induced current in InAs quantum wells in tilted quantizing magnetic fields. We have observed dramatic modification of the lineshape with increasing of in-plane component of magnetic field as well as with increasing of transverse built-in electric field in the well. Scenario of the modification shows that the energy spectrum asymmetry is determined by so-called toroidal moment of the system and is a function of Landau quantum number. Macroscopic self-organization of electrons under the conditions of quantum Hall effect has also been directly demonstrated in both linear and saturation regimes of the light absorption.  相似文献   

2.
An attempt is made to investigate theoretically the gate capacitance inn-channel inversion layers on ternary chalcopyrite semiconductors under both weak and strong electric field limits in the presence of a quantizing magnetic field, takingn-channel inversion layers on p-type Cd GaAs2 as examples. It is found, on the basis of the newly derived 2D electron spectra in inversion layers on the above class of semiconductors, for both weak and strong electric field limits, that the gate capacitances oscillate with the quantizing magnetic field and the crystal field splitting parameter effectively enhances the oscillatory spikes. It has also been observed that the oscillatory behaviour is in qualitative agreement with experimental observation as reported elsewhere for MOS structure of Hg1–xCdxTe. In addition, the corresponding results for inversion layers on parabolic semi-conductors are also obtained from the expressions derived.  相似文献   

3.
The conductivity of a quantum cylinder with a parabolic lateral confinement potential and a superstructure is studied under conditions where uniform static quantizing electric and magnetic fields are applied along the cylinder axis. The charge carriers are assumed to be scattered by optical phonons. The dependence of the current density along the superlattice axis on the dc magnetic field is obtained. It is shown that, under certain conditions, the so-called Stark-hybrid-phonon resonance appears due to the hybridization of the electronic energy spectrum. In turn, this gives rise to a sharply nonmonotonic magnetic-field dependence of the current density.  相似文献   

4.
The effect of the magnetic field on the generation of an electric current in a two-dimensional electronic ratchet is theoretically studied. Mechanisms of the formation of magnetically induced photocurrent are proposed for a structure with a two-dimensional electron gas (quantum well, graphene, or topological insulator) with a lateral asymmetric superlattice consisting of metallic strips on the external surface of the structure. The ratchet with the spatially oscillating magnetic field generated by the ferromagnetic lattice, as well as the nonmagnetic ratchet placed in the uniform magnetic field both classically weak and strong quantizing, is considered. It is established that the ratio of the amplitude of the magnetic oscillations of photocurrent to the ratchet photocurrent in zero field can exceed two orders of magnitude.  相似文献   

5.
The effect of quantizing electric field on plasma oscillations of two-dimensional electron gas in a system with a periodic potential has been theoretically investigated. The coupled-plasmon spectrum ω(q) is calculated for high temperatures (Δ ? T, where Δ is the conduction miniband width and T is temperature in energy units). The calculations are based on the quantum theory of plasma oscillations in the random-phase approximation, with allowance for the umklapp processes.  相似文献   

6.
A theory of far-infrared (FIR) magneto-optical intraband sp ± transitions of direct and indirect excitons in semiconductor coupled double quantum wells has been developed. The case of symmetric strained InxGa1−x As/GaAs quantum wells with nondegenerate valence band in the regime of both narrow and wide barriers has been analyzed. The energies and dipole matrix elements of transitions between the ground s and excited p ± states in a quantizing magnetic field B>2 T and electric field ℰ perpendicular to the quantum well plane have been studied. The regimes of direct (in a weak electric field) and indirect (in a strong electric field) transitions, and the transition between the direct and indirect regimes, have been investigated. Zh. éksp. Teor. Fiz. 113, 1446–1459 (April 1998)  相似文献   

7.
The effect of strong quantizing magnetic field on the equation of state of matter at the outer crust region of magnetars is studied. The density of such matter is low enough compared to the matter density at the inner crust or outer core region. Based on the relativistic version of semi-classical Thomas-Fermi-Dirac model in presence of strong quantizing magnetic field a formalism is developed to investigate this specific problem. The equation of state of such low density crustal matter is obtained by replacing the compressed atoms/ions by Wigner-Seitz cells with nonuniform electron density. The results are compared with other possible scenarios. The appearance of Thomas-Fermi induced electric charge within each Wigner-Seitz cell is also discussed.  相似文献   

8.
Theoretical and experimental works devoted to studying electron-phonon interaction in the two-dimensional electron gas of semiconductor heterostructures at low temperatures in the case of strong heating in an electric field under quasi-equilibrium conditions and in a quantizing magnetic field perpendicular to the 2D layer are considered.  相似文献   

9.
The nonlinear absorption of electromagnetic radiation by electrons in a quantizing magnetic field is investigated. The inclusion of multiphoton processes is shown to result in additional peaks in the absorption curve. The shape and arrangement of these peaks were found. The absorption is shown to depend on the electric field strength in the electromagnetic wave nonlinearly and nonmonotonically. The results obtained are in good agreement with experimental data.  相似文献   

10.
Turkevich  R. V.  Protogenov  A. P.  Chulkov  E. V. 《JETP Letters》2019,109(5):316-319
JETP Letters - The absorption of electromagnetic radiation in Dirac semimetals in a quantizing magnetic field has been considered. A universal broadening of the collisionless cyclotron damping line...  相似文献   

11.
We investigate the far-infrared (FIR) absorption of a two-dimensional electron gas in a periodically modulated quantizing magnetic field. The magnetic field varies along only one spatial direction and the external time-dependent electric field is linearly polarized along that axis. The mutual Coulomb interaction of the electrons is treated self-consistently in the ground state and in the absorption calculation within the Hartree approximation. The effects of the magnetic material on top of the heterostructure as a grating coupler is included in the time-dependent incident FIR electric field. We show that, similar to an electric modulation, the absorption can be directly correlated to the underlying electronic energy bands. In addition, the magnetic modulation leads to absorption spectra with a richer structure due to the quite different static response of the electron density to the modulation.  相似文献   

12.
Transient response of hot electrons in narrow-gap semiconductors to a step electric field in the presence of a longitudinal quantizing magnetic field has been studied at low temperatures using displaced Maxwellian distribution. The energy and momentum balance equations are used assuming acoustic phonon scattering via deformation potential responsible for the energy relaxation and elastic acoustic phonon scattering together with ionized impurity scattering for momentum relaxation. The calculations for the variation of drift velocity and electron temperature as functions of time are made for n-Hg0.8Cd0.2 Te in the extreme quantum limit at 1.5 K and 4.2 K. The momentum and energy relaxation times are found to be of the same order of magnitudes as with the experimental values. The magnetic field and lattice temperature dependences of the relaxation rates have been investigated.One of the authors, Suchandra Bhaumik, acknowledges the Council of Scientific and Industrial Research (New Delhi) for financial support.  相似文献   

13.
The effect of a magnetic field on the conductivity of band-gap graphene has been investigated. In the case of a non-quantizing field, the magnetic-field dependences of the conductivity and Hall conductivity have been found on the basis of the Boltzmann equation. The formula for the conductivity of graphene in a quantizing magnetic field at low temperatures has been derived within the Born approximation in the scattering potential. It has been shown that the magnetic-field dependence of the conductivity is oscillatory in this case.  相似文献   

14.
In this work the general expression of the electron transverse conductivity tensor of an electron-phonon system being in crossed strong electric and quantizing magnetic fields is considered starting from the Kubo-Kalashnikov formula. An explicit formula for the hot electron transverse conductivity σ xx is obtained and it is compared to a Titeica-type formula with the temperature of electrons replaced by an effective electron temperature depending on the electric field.  相似文献   

15.
Electron holography performed in situ inside a high resolution transmission electron microscope has been used to determine the magnitude and spatial distribution of the electric field surrounding individual field-emitting carbon nanotubes. The electric field (and hence the associated field emission current) is concentrated precisely at the tips of the nanotubes and not at other nanotube defects such as sidewall imperfections. The electric field magnitude and distribution are stable in time, even in cases where the nanotube field emission current exhibits extensive temporal fluctuations.  相似文献   

16.
Zitterbewegung (trembling motion) in thin-film topological insulators in the presence of a terahertz pump pulse has been considered. An analytical expression for the electric current density has been derived, which describes the electric current induced by the motion of an electron wave packet. The electron subsystem has been considered in the long-wavelength approximation, and the electromagnetic field has been described classically in the constant-pump approximation. The numerical analysis of the results has been carried out.  相似文献   

17.
The microwave breakdown has been studied for the case in which it is caused by the heating and subsequent thermal destruction of the micropoints present on the cathode surface subjected to the action of a rapidly varying electric field. The heating of a micropoint by the emission current induced by a microwave field has been numerically simulated using the two-temperature model. The delay time to breakdown has been calculated as a function of the frequency of the electric field oscillation for different micropoint geometries  相似文献   

18.
The possibility of magnetic ordering at dangling bonds in dislocation cores has been investigated theoretically. It has been experimentally shown that magnetic ordering in dislocations affects the spin-dependent effects occurring in dislocation crystals of silicon. It has been found that preliminary magnetic treatment of silicon crystals in a weak magnetic field leads to the suppression of the electroplastic effect induced in silicon crystals excited by an electric current. It has been assumed that a change in the microplasticity under the combined action of a magnetic field and an electric current is caused by a weakening of spin-dependent recombination at dislocation dangling bonds.  相似文献   

19.
This paper deals with the DC monopolar corona discharge in wire-to-plane geometry under variable humid air conditions. The classical formulas of Townsend commonly used for the current–voltage characteristics were used to determine the various corona parameters for the both polarities of the corona discharge. A circular biased probe has been adapted to the plane and is used to measure the ground plane current density and electric field during the monopolar corona discharge. A new approach to the problem of corona discharge in transmission system has been described in this paper. The effect of varying the humidity and wires diameter is also investigated. The values of the electric field and the current density are maximum beneath the corona wire and decrease when moving away from them and the current–voltage characteristics follow the quadratic Townsend's law. The experimental results show that the monopolar corona discharge is strongly affected by the air humidity. The current density and the electric field are measured and compared with the computed values. The agreement between the calculated values and those obtained experimentally is satisfactory. The per unit electric field and current density are also represented by a unique function.  相似文献   

20.
Bogusław Fugiel 《哲学杂志》2019,99(11):1327-1334
It has been shown that a side electrode perpendicular to the measurement ones can significantly enhance the transverse electric current in TGS. Such a current, measured in a zero external electric field, resembles the classic longitudinal one. However, the amplitude of the transverse current oscillation, observed while cooling and heating the sample, rises much more slowly with the time of the transverse electric field preliminary application. Such exposure to the transverse field is required prior to the measurements for the transverse current to be observed, in a similar way to a longitudinal field that is applied in order to achieve a single domain state before longitudinal pyroelectric current measurements. A huge difference in the time of reaction to the electric fields preliminarily applied in order to achieve the maximum amplitude of the current oscillations in both cases is the evidence that the transverse current cannot be considered to be originated just for geometrical reasons.  相似文献   

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