A number of time-resolved optical experiments probing and controlling the spin and charge dynamics of the high-mobility two-dimensional electron gas in a GaAs/AlGaAs heterojunction are discussed. These include time-resolved reflectivity, luminescence, transient grating, magneto-optical Kerr effect, and electro-optical Kerr effect experiments. The optical experiments provide information on the c...

To determine the state of spin polarization of the three-dimensional electron gas at very low densities and zero temperature, we calculate the energy versus spin polarization using diffusion quantum Monte Carlo methods with backflow wave functions and twist averaged boundary conditions. We find a second-order phase transition to a partially polarized phase at r(s) approximately 50+/-2. The magn...

We report strong localization of two-dimensional electron gas in LaAlO3/SrTiO3 epitaxial thin-film heterostructures grown on (LaAlO3)0.3-(Sr2AlTaO3)0.7 substrates by using pulsed laser deposition with in situ reflection high-energy electron diffraction. Using longitudinal and transverse magnetotransport measurements, we have determined that disorder at the interface influences the conduction be...

A narrow-band infrared phototransistor s14.8 mmd is designed and realized based on a GaAs/AlGaAs double-layer structure. An isolated island formed from the first quantum well sQWd works as a gate, which is capacitively coupled to the remote two-dimensional electron gas s2DEGd layer working as the source/drain channel. Incident radiation excites the intersubband transition within the isolated QW...

Accurate spectroscopy has driven advances in chemistry, materials science, and physics. However, despite their importance in the study of highly correlated systems, two-dimensional systems (2DES) have proven difficult to probe spectroscopically. Typical energy scales are on the order of a millielectron volt (meV), requiring high resolution, while correlated states of interest, such as those fou...

Energies of the ground state and low-lying excited states of the two-dimensional electron gas have been calculated by a transient-estimate Monte Carlo method. This is an exact fermion quantum Monte Carlo method that systematically improves upon the results of a variational energy without imposing nodal constraints. We focus upon the density rs51, where our previous variational Monte Carlo calcu...

A simple-and-analytic form for total energy (or ground-state energy) in the uniform three-dimensional electron gas, expressed as a function of any Wigner-Seitz radius rs and relative spin polarization ζ is obtained with a very good accuracy of 0.036% from the Stoner model and our interpolation between high-and-low density limits with use of a two-point approach for the correlation energy and sp...

Spin-Hall conductivity and Pauli susceptibility of 2D electron gas with Rashba spin-orbital interaction is studied theoretically in the semiclassical limit kFl 1. Static spin-Hall conductivity is shown to be zero for any nonvanishing disorder strength in the general case of the momentum-dependent Rashba velocity p and nonparabolic spectrum p . This result is derived both by an explicit diagramm...

An AlxGa1-xN/GaN two-dimensional electron gas structure with x = 0.13 deposited by molecular beam epitaxy on a GaN layer grown by organometallic vapor phase epitaxy on a sapphire substrate was characterized. Hall effect measurements gave a sheet electron concentration of 5.1x10 cm and a mobility of 1.9 x 10 cm/Vs at 10 K. Mobility spectrum analysis showed single-carrier transport and negligible...