arXiv subjects

S. E. Dizhur

Publications and source records attributed to S. E. Dizhur.

5 recordsLinked to original sources

arXiv2021

Anomalous Photoresponse of Heavily Doped GaAs/AlAs Superlattices with Electric Domains

The strong effect of weak interband illumination on tunneling transport in doped GaAs/AlAs superlattices was found under conditions of electric domain formation. The photoresponse at voltages below the threshold one (before the domain formation) did not observe. The phenomenon is referred to strong carrier depletion inside the triangular high-field domain. The domain modes transformations under the illumination were also found.

cond-mat.str-el↗

arXiv2020

Reflection of Electrons during Tunneling and an Intersubband Polaron in the 2D Electron System of a Delta-Layer in GaAs

Al-$δ$-GaAs structures are studied where tunneling to one or more subbands of the 2D electron system of a near-surface delta-doped layer is observed. Reflection of electrons at the threshold of the emission of LO-phonon is observed. This phenomenon occurs when a new subband is involved in the tunneling process and when intersubband transitions of the electrons in a 2D-system with the emission of LO-phonon are added to the inelastic tunneling within a single subband. It is shown that, under the conditions of an intersubband polaron resonance, the reflection processes dominate during tunneling into the delta-layer. If, however, tunneling from the delta-layer occurs, the reflection processes are observed when two subbands are occupied.

cond-mat.mes-hall↗

arXiv2020

2D-subband spectra variations under persistent tunneling photoconductivity condition in tunnel delta-GaAs/Al structures

2DEG states of Al/$δ$-GaAs structures were investigated in the persistent tunneling photoconductivity (PTPC) regime at low temperatures. "Thickening" of the unoccupied subbands to the ground state of 2DEG was observed at $T=4.2$~$K$. It was found that there is a uniform shift of the subband levels at $T=77$~$K$. The behavior of the persistent 2D states in tunneling spectra after various illumination and at different temperatures allows us to assume that there are two PTPC mechanisms, namely, the broadening of the potential well profile of the $δ$-layer and photoionization of the DX-centers.

cond-mat.mes-hall↗

arXiv2020

Magnons Parametric Pumping in Bulk Acoustic Waves Resonator

We report on the experimental observation of excitation and detection of parametric spin waves and spin currents in the bulk acoustic wave resonator. The hybrid resonator consists of ZnO piezoelectric film, yttrium iron garnet (YIG) films on gallium gadolinium garnet substrate, and a heavy metal Pt layer. Shear bulk acoustic waves are electrically excited in the ZnO layer due to piezoeffect at the resonant frequencies of the resonator. The magnetoelastic interaction in the YIG film emerges magnons (spin waves) excitation by acoustic waves either on resonator's eigenfrequencies or the half-value frequencies at supercritical power. We investigate acoustic pumping of magnons at the half-value frequencies and acoustic spin pumping from parametric magnons, using the inverse spin Hall effect in the Pt layer. The constant electric voltage in the Pt layer, depending on the frequency, the magnetic field, and the pump power, was systematically studied. We explain the low threshold obtained (~0.4 mW) by the high efficiency of electric power transmission into the acoustic wave in the resonator.

cond-mat.mes-hall↗

arXiv2002

Experimental Study of Pressure Influence on Tunnel Transport into 2DEG

We present the concept and the results of pilot measurements of tunneling in a system {Al/$δ_{Si}$-GaAs} under pressure up to 2 GPa at 4.2 K. The obtained results may indicate the following: the barrier height for {Al/$δ$-GaAs} equals to 0.86 eV at P=0 and its pressure coefficient is $3 meV/kbar$; charged impurity density in the delta-layer starts to drop from $4.5\times 10^{12} cm^{-2}$ down to $3.8\times 10^{12} cm^{-2}$ at about 1.5 GPa; metal-insulator transition may occur in 2DEG at about 2 GPa.

cond-mat↗