Publications (22)52.12 Total impact
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ABSTRACT: It is established that cyclotron resonance (CR) in a highquality GaAs/AlGaAs twodimensional electron system (2DES) originates as a \textit{pure} resonance, that does not hybridize with dimensional magnetoplasma excitations. The magnetoplasma resonances form a fine structure of the CR. The observed fine structure of the CR results from the interplay between coherent radiative and incoherent collisional mechanisms of 2D plasma relaxation. We show that the range of 2DES filling factors from which the phenomenon arises is intimately connected to the fundamental finestructure constant.  [Show abstract] [Hide abstract]
ABSTRACT: The dispersion of the volume relativistic magnetoplasma mode in a gated GaAs/AlGaAs quantum well is measured using a coupled resonators detection technique. The weakly damped relativistic mode exhibits an unusual zigzagshaped magnetodispersion dependence dictated by the diagonal component of the resistivity tensor $\rho_{xx}$. The plasma excitation easily hybridizes with photon modes due to a large spatial delocalization of its electromagnetic field. The effects of electron density and structure geometry on the excitation spectrum have been investigated.  [Show abstract] [Hide abstract]
ABSTRACT: The dispersion of plasma and magnetoplasma excitations in twodimensional electron systems with a closely spaced back gate is experimentally investigated using optical detection of microwave absorption. In disk samples, both cyclotron and edge screened magnetoplasmons are observed. It is established that the magneticfield behavior of both modes is in good agreement with the existing theory describing the dispersion of screened magnetoplasma excitations. It is shown that, in a strong magnetic field, the dispersion of screened magnetoplasma excitations is quadratic. This makes it possible to associate magnetoplasma waves with a quasiparticle with a mass, which possesses a number of unique properties. 
Article: Magnetoplasma excitations of twodimensional anisotropic heavy fermions in AlAs quantum wells
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ABSTRACT: The spectra of plasma and magnetoplasma excitations in a twodimensional system of anisotropic heavy fermions were investigated for the first time. The spectrum of microwave absorption by disklike samples of stressed AlAs quantum wells at low electron densities showed two plasma resonances separated by a frequency gap. These two plasma resonances correspond to electron mass principle values of $(1.10 \pm 0.05) m_0$ and $(0.20 \pm 0.01) m_0$. The observed results correspond to the case of a single valley strongly anisotropic Fermi surface. It was established that electron density increase results in population of the second valley, manifesting itself as a drastic modification of the plasma spectrum. We directly determined the electron densities in each valley and the intervalley splitting energy from the ratio of the two plasma frequencies.  [Show abstract] [Hide abstract]
ABSTRACT: The microwave response of a twodimensional electron system (2DES) covered by a conducting top gate is investigated in the relativistic regime for which the 2D conductivity $\sigma_{2 \rm{D}} > c/2\pi$. Weakly damped plasma waves are excited in the gated region of the 2DES. The frequency and amplitude of the resulting plasma excitations show a very unusual dependence on the magnetic field, conductivity, gate geometry and separation from the 2DES. We show that such relativistic plasmons survive for temperatures up to 300 K, allowing for new roomtemperature microwave and terahertz applications.  [Show abstract] [Hide abstract]
ABSTRACT: Dependence of cyclotron magnetoplasma mode relaxation time on electron concentration and temperature in the twodimensional electron system in GaAs/AlGaAs quantum wells has been studied. Comparative analysis of cyclotron and transport relaxation time has been carried out. It was demonstrated that with the temperature increase transport relaxation time tends to cyclotron relaxation time. It was also shown that cyclotron relaxation time, as opposed to transport relaxation time, has a weak electron density dependence. The cyclotron time can exceed transport relaxation time by an order of magnitude in a lowdensity range. 
Conference Paper: Highspeed THz semiconductor imaging camera
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ABSTRACT: A highspeed room temperature THz imaging system is developed. The sensor consists of an array (64×64) of plasmonic semiconductor detectors. The detectors have broadband responsivity of up to 20 V/W in the frequency range 10 GHz  1 THz. Pixeltopixel deviation of the sensor parameters is not larger than 20%. The sensor with an amplification electrical circuit provide shot times of 100 ms. The sensor is fabricated using standard semiconductor fab cycles. Therefore, the device is an ideal object for lowcost mass production. 
Article: Ultrastrong coupling of highfrequency twodimensional cyclotron plasma mode with a cavity photon
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ABSTRACT: The microwave transmission of a twodimensional electron stripe placed on a metallic patch resonator is studied. An ultrastrong coupling of the cyclotron plasmon with a resonator photon mode is identified in the regime, where the plasmon frequency is much greater than the photon frequency. In the zero magnetic field, it is established that the polariton frequency is determined exclusively by the resonator photon frequency and the electron system—resonator overlap factor. Polariton magnetodispersion is studied as a function of electron density, resonator sizes, and stripe dimensions.  [Show abstract] [Hide abstract]
ABSTRACT: We report observation of highQ resonance in the photoresponse of a detector embedded in the 2D photonic crystal slab (PCS) microcavity illuminated by terahertz radiation. The detector and PCS are fabricated from a single GaAs wafer in a unified process. The influence of the period of PCS lattice, microcavity geometry, and detector location on the resonant photoresponse is studied. The resonance is found to originate from coupling of the fundamental PCS microcavity photon mode to the detector. The phenomenon can be exploited to devise a spectrometeronachip for terahertz range.  [Show abstract] [Hide abstract]
ABSTRACT: Investigation of acoustic edge magnetoplasma excitations in micrometer twodimensional electron disks has been carried out. It has been shown that additional acoustic edge magnetoplasma modes associated with the existence of incompressible strips in the twodimensional electron system caused by Zeeman spin splitting can appear in the system at temperatures below the Zeeman energy. The magnetic dispersion of the first “spin” branch of acoustic edge magnetoplasmons has been studied. It has been shown that this mode vanishes as the filling factor ν = 1 is approached. The dependence of the relative amplitude of acoustic edge magnetoplasmons on the filling factor has also been investigated.  [Show abstract] [Hide abstract]
ABSTRACT: Acoustic edge magnetoplasmon (AEMP) modes are detected in a wide range of magnetic fields by the resonant microwave absorption technique. It is established that in the case of a smooth edge of a twodimensional electron system, the resonant signal is strongly enhanced with the AEMP excitation, whereas in the case of an abrupt edge, these modes are strongly damped. One fundamental mode and three AEMP modes are observed, and it is shown that the number of AEMP modes is directly related to the filling factor value. As a result, a sequence of abrupt terminations of AEMP modes is observed at the integer filling factors, in accordance with the number of edge compressible strips available in the electron system. Also the dependence of the relative AEMP amplitude versus the filling factor is addressed.  [Show abstract] [Hide abstract]
ABSTRACT: We demonstrate that the introduction of a defect in the form of an electron density step into a twodimensional electron system (2DES) locally rectifies the alternating potential of plasma waves. The rectification mechanism is active at temperatures up to room temperature. We observe photovoltage oscillations in a backgated 2DES with a density defect, when tuning the density under incident subterahertz radiation. The oscillations originate from the interference of 2D plasma waves excited by subterahertz radiation. The period of oscillations depends on the radiation wavelength. These phenomena can be exploited further to produce detectors/spectrometers for millimeter waves.  [Show abstract] [Hide abstract]
ABSTRACT: Resonant microwave absorption by twodimensional electrons has been measured using coplanar and strip methods. The influence of the edge of a twodimensional system on the dispersion of edge magnetoplasmons has been studied. It has been found that the edge width can be varied within wide limits (by almost two orders of magnitude) by changing the etching depth of the crystal. It has been shown that the edge of the electron system in the case of etching through the quantum well has a width of about 0.2 μm, whereas the edge in the case of shallow etching (e.g., down to the donor layer) is smooth and can be as wide as 12 μm. The influence of a logarithmic factor, depending on the edge width of the electron system, on edge magnetoplasma excitations dispersion has been studied.  [Show abstract] [Hide abstract]
ABSTRACT: In this paper, the highfrequency ($f=0.05$\char21{}10 GHz) magnetoresistance of a twodimensional electron system is studied in the regime of microwaveinduced resistance oscillations (MIRO). For this purpose, we employed a technique based on measuring the attenuation of a broadband coplanar transmission line placed on the sample surface, with the sample simultaneously being subjected to external microwave irradiation of frequency $F=40$\char21{}140 GHz. In the $f$\leqslant${}1$ GHz probe frequency range, the coplanar waveguide transmission exhibits several features that repeat the MIRO measured on the same sample using the conventional dc transport technique. At higher probe signal frequencies $f$, the MIRO features in transmission are significantly suppressed. In particular, for a microwave irradiation frequency of $F=80$ GHz, the first two features of the waveguide transmission decrease by an order of magnitude at ${f}_{1}=3.0$ GHz and ${f}_{2}=1.5$ GHz, respectively. 
Article: Observation of hybrid plasmonphoton modes in microwave transmission of coplanar microresonators
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ABSTRACT: Microwave transmission of a coplanar microresonator deposited on a sample surface over a twodimensional electron system has been studied. The transmission signal reveals a series of resonances corresponding to the excitation of hybrid cavity plasmonphoton modes, and ultrastrong plasmonphoton coupling has been realized. The hybridization frequency (Rabi frequency) is shown to be anomalously larger than the frequencies of unperturbed modes and it reaches values of up to $25$ GHz. The effect of electron density and magnetic field on the excitation spectrum of cavity polariton has been investigated. 
Article: Experimental investigation of plasma excitations in asymmetric stripes of twodimensional electrons
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ABSTRACT: The plasmon microwave response of symmetric and asymmetric stripes of twodimensional electrons with different boundary conditions has been studied. The symmetric case corresponds to stripes either without ohmic contacts or with ohmic contacts on both sides, while the contact in asymmetric stripes is present only on one side. It has been shown that there is a frequency shift of the observed plasma modes in asymmetric stripes. The lowestfrequency mode becomes a previously unobserved mode for which the quarter wavelength of the plasmon coincides with the length of the stripe. The behavior of the lowest mode and its multiple frequencies in asymmetric stripes has been studied under variation of the magnetic field, electron density, and temperature and size of the stripes. The results indicate that all plasma modes in symmetric and asymmetric stripes have the same physical nature.  [Show abstract] [Hide abstract]
ABSTRACT: A miniature high speed tera and gigahertz electromagnetic radiation detector/spectrometer has been created. The operation principle is based on the excitation of distinct sets of plasma modes in the twodimensional electron system (2DES) of semiconductor AlGaAs/GaAs heterostructure with embedded nonlinear defect. The technique performs up to room temperature and may be used in variety of applications.  [Show abstract] [Hide abstract]
ABSTRACT: The nonlinear plasmon response of a twodimensional electron system with an incorporated defect to monochromatic and bichromatic microwave radiation has been investigated. The operation of an electronic device (mixer) based on the plasmon response with a record operational speed has been demonstrated and analyzed. It has been found that the system response time is no more than τ = 25 ps. It has been shown that the nonlinear response of the system is caused by a new physical mechanism of nonlinearity induced by the presence of an inhomogeneity in the electron system.  [Show abstract] [Hide abstract]
ABSTRACT: Plasmonic crystal effects analogous to photonic crystal phenomena such as zone folding and gap opening were observed for edge magnetoplasmons in a twodimensional electron system with a periodically corrugated boundary at microwave frequencies. Magnetic field dependent photovoltage data provide unequivocal evidence for Bragg reflection. Band gaps up to fifth order were observed. These gaps were investigated as a function of the electron density, the magnetic field, and the periodicity to demonstrate the tunability of the dispersive properties of these plasmonic crystals.  [Show abstract] [Hide abstract]
ABSTRACT: Magnetic oscillations of the photovoltage in a twodimensional electron system with the back gate, exposed to microwave radiation, are studied. The oscillations result from the interference of screened edge magnetoplasmons (EMPs). The mean free path of the EMPs is quantitatively determined by analyzing the dependence of the oscillation amplitude on the electron density. The dependences of the mean free path of the EMPs on the twodimensional electron density, microwave frequency, electron relaxation time, and the magnetic field are studied. It is found that the dependences agree qualitatively with the known theoretical calculations. PACS numbers67.57.Lm76.60.k
Publication Stats
131  Citations  
52.12  Total Impact Points  
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Institutions

20062015

Institute of Solid State Physics RAS
Chernogolovka, Moskovskaya, Russia


20092012

Russian Academy of Sciences
 Institute of Solid State Physics
Moskva, Moscow, Russia


20072008

Max Planck Institute for Solid State Research
Stuttgart, BadenWürttemberg, Germany
