Igor V Kukushkin

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We compare the results of the transport and time-resolved magnetoluminescence measurements in disordered two-dimensional ͑2D͒ electron systems in GaAs-Al x Ga 1Ϫx As heterostructures in the extreme quantum limit, particularly in the vicinity of the metal-insulator transition ͑MIT͒. At filling factors ␯Ͻ1, the optical signal has two components: the(More)
Coherent condensate states of particles obeying either Bose or Fermi statistics are in the focus of interest in modern physics. Here we report on condensation of collective excitations with Bose statistics, cyclotron magnetoexcitons, in a high-mobility two-dimensional electron system in a magnetic field. At low temperatures, the dense non-equilibrium(More)
Semiconductor and plasmonic nanostructures have attracted considerable attention during the last decade. Semiconductors are the basis of today's information technology because of the possibility of tailoring electrical and optical properties on a detailed level. An elementary optical excitation in semiconductors is the electron-hole pair (exciton) with(More)
An experimental technique for the indirect manipulation and detection of electron spins entangled in two-dimensional magnetoexcitons has been developed. The kinetics of the spin relaxation has been investigated. Photoexcited spin-magnetoexcitons were found to exhibit extremely slow relaxation in specific quantum Hall systems, fabricated in high mobility(More)
Inelastic light scattering spectroscopy discloses a novel type of cyclotron spin-flip excitation in a quantum Hall system around the nu = 1/3 filling. The excitation energy follows qualitatively the degree of electron spin polarization, reaching a maximum value at nu = 1/3. This characterizes the new excitation as a nu = 1/3 ferromagnet eigenmode. The mode(More)
The rich correlation physics in two-dimensional (2D) electron systems is governed by the dispersion of its excitations. In the fractional quantum Hall regime, excitations involve fractionally charged quasi particles, which exhibit dispersion minima at large momenta referred to as rotons. These rotons are difficult to access with conventional techniques(More)
We observe a new type of magneto-oscillations in the photovoltage and the longitudinal resistance of a two-dimensional electron system. The oscillations are induced by microwave radiation and are periodic in magnetic field. The period is determined by the microwave frequency, the electron density, and the distance between potential probes. The phenomenon is(More)
It is occasionally possible to interpret strongly interacting many-body systems within a single-particle framework by introducing suitable fictitious entities, or 'quasi-particles'. A notable recent example of the successful application of such an approach is for a two-dimensional electron system that is exposed to a strong perpendicular magnetic field. The(More)
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