I. V. Kukushkin

Slow spin relaxation in a quantum Hall ferromagnet state

(Received 18 October 2013; revised manuscript received 27 March 2014; published 10 April 2014)Electron spin relaxation in a spin-polarized quantum Hall state is studied. Long spin-relaxation times that areat least an order of magnitude longer than those measured in previous experiments were observed and explainedwithin the spin-exciton relaxation formalism. The absence of any dependence of the spin-relaxation time on theelectron temperature and on the spin-exciton density, and a specific dependence on the magnetic field indicate adefiniterelaxationmechanism—spin-exciton annihilationmediatedbyspin-orbitcouplingandasmoothrandompotential.DOI: 10.1103/PhysRevB.89.161301 PACS number(s): 73

Optical probing of MgZnO/ZnO heterointerface confinement potential energy levels

Low-temperature photoluminescence and reflectance measurements were employed to study the optical transitions present in two-dimensional electron systems confined at MgxZn1–xO/ZnO heterojunctions. Transitions involving A- and B-holes and electrons from the two lowest subbands formed within the confinement potential are detected. In the studied density range of 2.0–6.5u2009×u20091011u2009cm−2, the inter-subband splitting is measured and the first excited electron subband is shown to be empty of electrons.

Artificially Constructed Plasmarons and Plasmon-Exciton Molecules in 2D Metals

Resonant optical excitation was used to create a macroscopic nonequilibrium ensemble of dark excitons with an unprecedented long lifetime in a two-dimensional electron system placed in a quantizing magnetic field. Exotic three-particle and four-particle states, plasmarons and plasmon-exciton molecules, coupled with the surrounding electrons through the collective plasma oscillations are engineered. Plasmarons and plasmon-exciton molecules are manifested as new features in the recombination spectra of nonequilibrium systems.

Observation of collective excitations in MgZnO/ZnO two-dimensional electron systems by resonant Raman scattering

The neutral excitations in two-dimensional electron systems (2DES) confined at

Optical manifestation of the Stoner ferromagnetic transition in two-dimensional electron systems

{mathrm{Mg}}_{x}{mathrm{Zn}}_{1ensuremath{-}x}mathrm{O}/text{ZnO}

Goldstone mode stochastization in a quantum Hall ferromagnet

heterojunctions were studied by a resonant inelastic light scattering (ILS) technique. At zero magnetic field the ILS spectra of intra- and intersubband collective excitations are detected in the wavelength range close to the ZnO direct band gap. The intersubband spectrum is represented by collective modes of charge- and spin-density excitations along with single-particle excitation continuum. The energies of these excitations were characterized on the series of samples and shown to grow sublinearly with the two-dimensional electron density. The intrasubband 2D plasmon was observed at plasma frequency and its square-root momentum dispersion was ascertained. Strong electron-electron correlations are manifested in the energy structure of intersubband excitations. Depolarization and excitonic contributions to the charge- and spin-density excitation energies are extracted in the wide range of 2D-electron densities. The negative excitonic contribution dominates among the many-particle energy terms and results in an unusual hierarchy of 2DES intersubband collective excitation energies.

Long-range non-diffusive spin transfer in a Hall insulator

We perform a magneto-optical study of a two-dimensional electron systems (2DES) in the regime of the Stoner ferromagnetic instability for even quantum Hall filling factors on Mg

Observation of microwave induced resistance and photovoltage oscillations in MgZnO/ZnO heterostructures

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Electron g -factor anisotropy in an AlAs quantum well probed by ESR

Zn

Microwave magnetoplasma resonances of two-dimensional electrons in MgZnO/ZnO heterojunctions

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