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1.
The quantum states of carriers in 2D doubly periodic n-type semiconducting superlattices without spatial inversion symmetry in an external magnetic field are calculated in the one-electron approximation. It is shown that the spin-orbit interaction and spin splitting in the magnetic field may lead to the occurrence of the photovoltaic effect in a 2D electron gas without an inversion center and to a nonzero spin magnetization of the electron gas in the plane perpendicular to the magnetic field. 相似文献
2.
《Superlattices and Microstructures》1993,13(1):55-60
We investigate the dephasing dynamics in semiconductor superlattices using time-resolved four-wave mixing. The signals show a periodic modulation which can be related to Bloch oscillations in the superlattice miniband. The oscillation frequency is strongly dependent on the applied field, in agreement with theoretical expectation. At high fields, the dephasing times become very short due to field-induced scattering. 相似文献
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Governale M 《Physical review letters》2002,89(20):206802
We present results on the effects of spin-orbit coupling on the electronic structure of few-electron interacting quantum dots. The ground-state properties as a function of the number of electrons in the dot N are calculated by means of spin-density functional theory. We find a suppression of Hund's rule due to the competition of the Rashba effect and exchange interaction. Introducing an in-plane Zeeman field leads to a paramagnetic behavior of the dot in a closed-shell configuration and to spin texture in space. 相似文献
6.
JETP Letters - Quantization rules have been obtained for the Hall conductance of fully occupied Landau subbands of the two-dimensional electron gas with the Dresselhaus spin-orbit interaction in a... 相似文献
7.
Quantization rules have been obtained for the Hall conductance of fully occupied Landau subbands of the two-dimensional electron gas with the Dresselhaus spin-orbit interaction in a periodic electrostatic field of a superlattice and a transverse magnetic field. The spin-orbit interaction mixes states of different magnetic subbands and changes the quantization rule for the Hall conductance compared to spinless particles. The calculations have been performed for the two-dimensional electrons in the structures with both a weak (AlGaAs/GaAs) and sufficiently strong (GaAs/In0.23Ga0.77As) spin-orbit interaction and Zeeman splitting. It has been found that the distribution of the Hall conductance among the magnetic subbands depends on the geometric parameters of the superlattices and promptly changes upon the touching of the adjacent subbands in the spectrum. The quantization rule for the Hall conductance in real semiconductor structures with relatively strong spin-orbit interaction has been shown to differ from that calculated by Thouless et al. [Phys. Rev. Lett. 49, 405 (1982)] for the systems without the spin-orbit interaction and Zeeman effect. 相似文献
8.
We report a numerical investigation of the Anderson transition in two-dimensional systems with spin-orbit coupling. An accurate estimate of the critical exponent nu for the divergence of the localization length in this universality class has to our knowledge not been reported in the literature. Here we analyze the SU(2) model. We find that for this model corrections to scaling due to irrelevant scaling variables may be neglected permitting an accurate estimate of the exponent nu=2.73+/-0.02. 相似文献
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K. L. Litvinenko I. Okhrimenko K. Köhler V. G. Lysenko K. Leo F. Löser 《JETP Letters》1998,67(10):869-874
The variation of the spectral shape of the four-wave mixing signal in GaAs/AlGaAs superlattices was studied experimentally
and theoretically. It was shown that in an external electric field, leading to anti-crossing of the levels of heavy and light
excitons, sawtooth oscillations of the energy position of the levels are observed. These oscillations are due to the inhomogeneous
broadening of the states participating in the Bloch oscillations.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 10, 820–825 (25 May 1998) 相似文献
11.
Maria Stȩślicka 《Physics letters. A》1976,57(3):255-256
In an electric field typical for field ion microscopy, true surface states can exist. Their shift towards higher energies can be quite significant, and moreover, additional surface levels at still higher energies can appear. 相似文献
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V. Ya. Demikhovskii A. A. Perov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(2):223-225
The Hall conductance of a two-dimensional electronic system with Rashba spin-orbit coupling in the presence of an external periodic potential of a superlattice and a perpendicular magnetic field has been calculated. The calculations were performed for an electron gas with parameters typical both of a system with weak spin-orbit coupling (AlGaAs/GaAs) and a system with relatively strong Rashba coupling (InGaAs/InAs). 相似文献
13.
K.J Cheng 《Physics letters. A》1985,112(8):392-396
The capillary oscillations of a conducting spheroidal drop with small eccentricity in an electric field are studied. The effect of the electric field is to lower the natural frequencies of oscillations and the damping coefficient. 相似文献
14.
Using the transfer matrix method, we investigate the electron transmission over multiple-well semiconductor superlattices with Dresselhaus spin-orbit coupling in the potential-well regions. The superlattice structure enhances the effect of spin polarization in the transmission spectrum. The minibands of multiple-well superlattices for electrons with different spin can be completely separated at the low incident energy, leading to the 100% spin polarization in a broad energy windows, which may be an effective scheme for realizing spin filtering. Moreover, for the transmission over n-quantum-well, it is observed that the resonance peaks in the minibands split into n-folds or (n−1)-folds depending on the well-width and barrier-thickness, which is different from the case of tunneling through n-barrier structure. 相似文献
15.
《Superlattices and Microstructures》1999,25(1-2):419-424
Time-resolved photoluminescence (PL), steady-state PL, and electroluminescence (EL) techniques have been used to characterize the carrier relaxation processes and carrier escape mechanisms in self-assembled InAs/GaAs quantum dot (SAQD) p-i-n structures under reverse bias. The measurements were performed between 5 K and room temperature on a ring mesa sample as a function of bias. At 100 K, the PL decay time originating from the n = 1 SAQD decreases with increasing reverse bias from ∼3 ns under flat band condition to∼ 400 ps for a bias of −3 V. The data can be explained by a simple model based on electron recombination in the quantum dots (QDs) or escape out of the dots. The escape can occur by one of three possible routes: direct tunneling out of the distribution of excited electronic levels, thermally assisted tunneling of ground state electrons through the upper excited electronic states or thermionic emission to the wetting layer. 相似文献
16.
Elementary excitations of a new type in paramagnetic materials with spin-orbit interaction are predicted theoretically within the Rashba model and named the spin remagnetization waves. These normal modes arise from rotation of the spin magnetic moment in a medium where the electric field contains a constant component and a traveling wave component. A method is proposed for exciting these vibrations by illuminating the sample with an oscillating interference pattern. The spin remagnetization waves can be experimentally detected by measuring the dependence of the current through the sample on the oscillation frequency and wave vector of the interference pattern. 相似文献
17.
G. M. Min’kov O. É. Rut A. V. Germanenko 《Journal of Experimental and Theoretical Physics》1997,85(2):292-299
We study tunneling conductivity oscillations in a magnetic field in narrow-gap p-HgCdTe-oxide-metal (Yb, Al) structures. In tunnel structures with Yb we detect two types of tunneling conductivity oscillations.
The first is related to the crossing of the Landau levels of two-dimensional (2D) states localized in the surface quantum well of the semiconductor, and has an energy E
F+eV, where E
F is the Fermi energy of the semiconductor and V is the bias voltage; the second has an energy E
F. We find that in such structures with an asymmetric quantum well there is strong spin-orbit splitting in the spectrum of
the 2D states. In p-HgCdTe-oxide-Al tunnel structures the surface potential is much weaker and only oscillations of the first type are observed.
We find that in such structures there is only one spin state of the 2D carriers, while the second is pushed into the continuous spectrum because of strong spin-orbit coupling. To analyze the experimental
results we calculate the spectrum of 2D states localized in the surface quantum well in a semiconductor with a Kane dispersion law. We find that all the experimental
results are in good agreement with the results of calculations. Finally, we discuss the features of “kinematically coupled”
states in an asymmetric quantum well.
Zh. éksp. Teor. Fiz. 112, 537–550 (August 1997) 相似文献
18.
The competition between the Zeeman energy and the Rashba and Dresselhaus spin-orbit couplings is studied for fractional quantum Hall states by including correlation effects. A transition of the direction of the spin polarization is predicted at specific values of the Zeeman energy. We show that these values can be expressed in terms of the pair-correlation function, and thus provide information about the microscopic ground state. We examine the particular examples of the Laughlin wave functions and the 5/2-Pfaffian state. We also include effects of the nuclear bath. 相似文献
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V. L. Al'perovich A. S. Terekhov V. A. Tkachenko O. A. Tkachenko N. T. Moshegov A. I. Toropov A. S. Yaroshevich 《Physics of the Solid State》1999,41(1):143-147
The photocurrent was measured as a function of the external electric field in short-period AlAs/GaAs superlattices for various
photon energies. Transport resonances, whose positions do not depend on the photon energy, were observed in these dependences
together with optical resonances due to interband transitions in Wannier-Stark levels. It is shown that the transport resonances
are due to tunneling of photoelectrons from the p-GaAs contact region into the first level in GaAs wells located 2–5 lattice periods from the contact layer.
Fiz. Tverd. Tela (St. Petersburg) 41, 159–164 (January 1999) 相似文献