M. L. Savchenko

TU Wien

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

D. A. Kozlov

Institute of Semiconductor Physics

Z. D. Kvon

Institute of Semiconductor Physics

S. A. Dvoretsky

Institute of Semiconductor Physics

НН

Н. Н. Михайлов

Russian Academy of Sciences

A. Pimenov

TU Wien

ИА

И. А. Дмитриев

University of Regensburg

A. Shuvaev

TU Wien

Z. D. Kvon

Novosibirsk State University

НН

Н. Н. Михайлов

Gubkin Russian State University of Oil and Gas

Sergey Ganichev

University of Regensburg

Cooperative Institutions

Institute of Semiconductor Physics

Russian Academy of Sciences

Novosibirsk State University

Siberian Branch of the Russian Academy of Sciences

University of Regensburg

Ioffe Institute

Laboratoire National des Champs Magnétiques Intenses

Centre National de la Recherche Scientifique

National Research Tomsk State University

TU Wien

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Спектры пропускания квантовых ям и пленок на основе HgTe в дальнем ИК-диапазоне

Физика твердого тела (2018)

M. L. Savchenko N. N. Vasil’ev А.С. Ярошевич D. A. Kozlov Z. D. Kvon

AbstractStrained 80-nm-thick HgTe films belong to a new class of materials referred to as three-dimensional topological insulators (i.e., they have a bulk band gap and spin-nondegenerate surface states). Though there are a number of studies devoted to analysis of the properties of surface states using both transport and magnetooptical techniques in the THz range, the information about direct optical transitions between bulk and surface bands in these systems has not been reported. This study is devoted to the analysis of transmission and reflection spectra of HgTe films of different thicknesses in the far-infrared range recorded in a wide temperature range in order to detect the above interband transitions. A peculiarity at 15 meV, which is sensitive to a change in the temperature, is observed in spectra of both types. Detailed analysis of the data obtained revealed that this feature is related to absorption by HgTe optical phonons, while the interband optical transitions are suppressed.

Reflection

Surface States

Topological insulator

Atmospheric temperature range

10.21883/ftt.2018.04.45692.309

Cite

Citations (2)

Sign-alternating photoconductivity and magnetoresistance oscillations induced by terahertz radiation in HgTe quantum wells

Physical review. B./Physical review. B (2018)

M. Otteneder И. А. Дмитриев S. Candussio M. L. Savchenko D. A. Kozlov

We report on the observation of terahertz radiation induced photoconductivity and of terahertz analog of the microwave-induced resistance oscillations (MIRO) in HgTe-based quantum well (QW) structures of different width. The MIRO-like effect has been detected in QWs of 20 nm thickness with inverted band structure and a rather low mobility of about $3\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{2}$/V s. In a number of other structures with QW widths ranging from 5 to 20 nm and lower mobility we observed an unconventional nonoscillatory photoconductivity signal which changes its sign upon magnetic field increase. This effect was observed in structures characterized by both normal and inverted band ordering, as well as in QWs with critical thickness and linear dispersion. In samples having Hall bar and Corbino geometries an increase of the magnetic field resulted in a single and double change of the sign of the photoresponse, respectively. We show that within the bolometric mechanism of the photoresponse these unusual features imply a nonmonotonic behavior of the transport scattering rate, which should decrease (increase) with temperature for magnetic fields below (above) the certain value. This behavior is found to be consistent with the results of dark transport measurements of magnetoresistivity at different sample temperatures. Our experiments demonstrate that photoconductivity is a very sensitive probe of the temperature variations of the transport characteristics, even those that are hardly detectable using standard transport measurements.

Photoconductivity

Bar (unit)

10.1103/physrevb.98.245304

Cite

Citations (11)

Quantum capacitance of a three-dimensional topological insulator based on HgTe

Low Temperature Physics (2017)

D. A. Kozlov D. Bauer J. F. Ziegler R. Fischer M. L. Savchenko

The quantum capacitance that directly characterizes the density of states of highly mobile Dirac two-dimensional states formed on the surface of a stressed HgTe film is studied experimentally. It is shown that, as opposed to the oscillations in the magnetotransport to which all the existing types of carriers contribute, the quantum oscillations observed in the magnetic capacitance correspond to electrons on the upper surface of the film. Thus, capacitance spectroscopy is a selective technique for studying the properties of an individual topological surface, even when a large number of bulk carriers are present. Because of this feature, for the first time we have obtained data on the phase shift in the Shubnikov-de Haas oscillations usually associated with the Berry phase for an isolated Dirac cone and found its dependence on the location of the Fermi level.

Topological insulator

Surface States

Quantum capacitance

10.1063/1.4983330

Cite

Citations (0)

Terahertz Cyclotron Photoconductivity in a Highly Unbalanced Two-Dimensional Electron–Hole System

JETP Letters (2018)

M. L. Savchenko Z. D. Kvon S. Candussio Н. Н. Михайлов С. А. Дворецкий

Photoconductivity

Cyclotron resonance

Landau quantization

Solid-state physics

10.1134/s0021364018160075

Cite

Citations (6)

Optical Shubnikov - de Haas oscillations in 2D electron systems

arXiv (Cornell University) (2024)

M. L. Savchenko Jan Gospodarič A. Shuvaev И. А. Дмитриев V. Dziom

We report on dynamic Shubnikov - de Haas (SdH) oscillations that are measured in the optical response, sub - terahertz transmittance of two-dimensional systems, and reveal two distinct types of oscillation nodes: "universal" nodes at integer ratios of radiation and cyclotron frequencies and "tunable" nodes at positions sensitive to all parameters of the structure. The nodes in both real and imaginary parts of the measured complex transmittance are analyzed using a dynamic version of the static Lifshitz-Kosevich formula. These results demonstrate that the node structure of the dynamic SdH oscillations provides an all-optical access to quantization- and interaction-induced renormalization effects, in addition to parameters one can obtain from the static SdH oscillations.

10.48550/arxiv.2402.05879

Cite

Citations (0)

Optical realization of magneto-intersubband oscillations

Applied Physics Letters (2024)

M. L. Savchenko А. А. Быков A. Shuvaev A. K. Bakarov A. Pimenov

We report on the optical realization of the magneto-intersubband oscillations that have been measured in the sub-terahertz transmittance of a GaAs quantum well with two subbands occupied. Following their dc analogue, the oscillations are periodic in the inverse magnetic field with the period governed by the subband gap. Their magnitude and polarization dependence accurately follow the presented simplified version of the dynamic magneto-intersubband oscillations equation that naturally combines dc magneto-intersubband oscillations with microwave-induced resistance oscillations. Simultaneously measured photoresistance also reveals its strong sensitivity to the sign of the circular polarization, proving the used theoretical modeling.

Realization (probability)

10.1063/5.0204388

Cite

Citations (0)

Transport properties of a 1000 nm HgTe film: the interplay of surface and bulk carriers

Journal of Physics Condensed Matter (2023)

M. L. Savchenko D. A. Kozlov N. N. Vasil’ev Н. Н. Михайлов S. A. Dvoretsky

We report on systematic study of transport properties of a 1000 nm HgTe film. Unlike thinner and strained HgTe films, which are known as high-quality three-dimensional topological insulators, the film under study is much thicker than the limit of pseudomorphic growth of HgTe on a CdTe substrate. Therefore, the 1000 nm HgTe film is expected to be fully relaxed and has the band structure of bulk HgTe, i.e. a zero gap semiconductor. Additionally, the system is characterized by the bands inversion, so that the two-dimensional topological surface states (TSSs) are expected to exist. To check this claim we studied classical and quantum transport response of the system. We demonstrate that by tuning the top-gate voltage one can change the electron-dominating transport to the hole one. The highest electron mobility is found to be more than300×103 cm2 Vs-1. The system exhibits Shubnikov-de Haas (SdH) oscillations with a complicated pattern and shows up to five independent frequencies in corresponding Fourier spectra. These Fourier peaks are attributed to the TSSs, Volkov-Pankratov states and spin-degenerate bulk states in the accumulation layer near the gate. The observed peculiarities of the quantum transport are the strong SdH oscillations of the Hall resistance, and the suppressed oscillatory response of the TSSs.

Topological insulator

Surface States

Cadmium telluride photovoltaics

10.1088/1361-648x/acd5a2

Cite

Citations (2)

Scattering anisotropy in HgTe (013) quantum well

Applied Physics Letters (2022)

D. A. Khudaiberdiev M. L. Savchenko D. A. Kozlov Н. Н. Михайлов Z. D. Kvon

We report on a detailed experimental study of the electron transport anisotropy in HgTe (013) quantum well of 22 nm width in the directions [100] and [031¯] as the electron density function n. The anisotropy is absent at the minimal electron density near a charge neutrality point. The anisotropy increases with the increase in n and reaches about 10% when the Fermi level is within the first subband H1. There is a sharp increase in the anisotropy (up to 60%) when the Fermi level reaches the second subband E2. We conclude that the first effect is due to the small intra-subband anisotropic interface roughness scattering, and the second one is due to the strongly anisotropic inter-subband roughness scattering, but the microscopical reason for such a strong change in the anisotropy remains unknown.

10.1063/5.0101932

Cite

Citations (4)

Nonlinear helicity anomalies in the cyclotron resonance photoresistance of two-dimensional electron systems

arXiv (Cornell University) (2023)

Erwin Mönch Sophia Schweiss I. Yahniuk M. L. Savchenko И. А. Дмитриев

Our studies of the cyclotron resonance (CR) photoresistance in GaAs-based two-dimensional electron systems (2DES) reveal an anomalously low sensitivity to the helicity of the incoming circularly polarized terahertz radiation. We find that this anomaly is strongly intensity dependent, and the ratio of the low-temperature photoresistance signals for the CR-active (CRA) and CR-inactive (CRI) polarities of magnetic field increases with lowering power, but, nevertheless, remains substantially lower than expected from conventional theory assuming interaction of the plane electromagnetic wave with the uniform 2DES. Our analysis shows that all data can be well described by the nonlinear CR-enhanced electron gas heating in both CRA and CRI regimes. This description, however, requires a source of anomalous absorption of radiation in the CRI regime. It can stem from evanescent electromagnetic fields originating from the near-field diffraction within or in the vicinity of the quantum well hosting the 2DES.

Helicity

Cyclotron resonance

Anomaly (physics)

10.48550/arxiv.2311.05468

Cite

Citations (0)

Optical realization of magneto-intersubband oscillations

arXiv (Cornell University) (2024)

M. L. Savchenko А. А. Быков A. Shuvaev A. K. Bakarov A. Pimenov

We report on the optical realization of the magneto-intersubband oscillations that have been measured in the sub-terahertz transmittance of a GaAs quantum well with two subbands occupied. Following their dc analogue, the oscillations are periodic in the inverse magnetic field with the period governed by the subband gap. Their magnitude and polarization dependence accurately follow the presented simplified version of the dynamic magneto-intersubband oscillations equation that naturally combines dc magneto-intersabband oscillations with microwave-induced resistance oscillations (MIRO). Simultaneously measured photoresistance also reveals its strong sensitivity to the sign of the circular polarization, proving the used theoretical modeling.

Realization (probability)

Magneto

10.48550/arxiv.2402.06453

Cite

Citations (0)