Related papers: Field-Effect Persistent Photoconductivity
Cyclotron resonance at microwave frequencies is used to measure the band mass (m_b) of the two-dimensional holes (2DH's) in carbon-doped (100) GaAs/AlxGa1-xAs heterostructures. The measured m_b shows strong dependences on both the 2DH…
The field-effect-induced modulation of transport properties of 2-dimensional electron gases residing at the LaAlO$_3$/SrTiO$_3$ and LaGaO$_3$/SrTiO$_3$ interfaces has been investigated in a back-gate configuration. Both samples with…
The photoluminescence (PL) spectrum of a two-dimensional electron gas (2DEG) in the fractional quantum Hall regime is studied as a function of the separation $d$ between the electron and valence hole layers. The abrupt change in the…
Electrical spin transport and accumulation have been measured in highly Si doped Al0.3Ga0.7As utilizing a lateral spin transport device. Persistent photoconductivity allows for the tuning of the effective carrier density of the channel…
We have investigated the magnetoresistance of strongly asymmetric double-well structures formed by a thin AlGaAs barrier grown far from the interface in the GaAs buffer of standard heterostructures. In magnetic fields oriented parallel to…
We report an experimental study of quantum conductivity corrections in a low mobility, high density two-dimensional electron gas in a AlGaAs/GaAs/AlGaAs quantum well in a wide temperature range (1.5K - 110K). This temperature range covers…
One of the basic optoelectronic characteristics is the absorption of any optoelectronic device or material. We present the characteristics of pure GaAs and the deviation of ideal spectra. Due to crystal defects, vacancies, impurities, etc.,…
Modulation-doped GaAs v-groove quantum wires (QWRs) have been fabricated with novel electrical contacts made to two-dimensional electron-gas (2DEG) reservoirs. Here, we present longitudinal photocurrent (photoconductivity/PC) spectroscopy…
When a high electron mobility transistor is illuminated, the absorbed photons excite electron-hole pairs. The generated pairs are separated by the built in field in such a way that the electrons end up in the quantum well generating a…
Photoluminescence measurements were carried out on Be $\delta$-doped GaAs/Al$_{0.33}$Ga$_{0.67}$As heterostructure at 1.6 K in magnetic fields ($B$) up to 5 T. Luminescence originating from recombination of a two-dimensional electron gas…
We present here the electronic structure and optical properties of InGaAs quantum wells with barrier doped with Manganese. We calculated the electronic states and optical emission within the envelope function and effective mass…
Two-dimensional electrons in AlAs quantum wells occupy multiple conduction-band minima at the X- points of the Brillouin zone. These valleys have large effective mass and g-factor compared to the stan-dard GaAs electrons, and are also…
Alkali vapor cells with antirelaxation coating (especially paraffin-coated cells) have been a central tool in optical pumping and atomic spectroscopy experiments for 50 years. We have discovered a dramatic change of the alkali vapor density…
We investigate the proximity effect in InAs nanowire (NW) junctions with superconducting contacts made of Al. The carrier density in InAs is tuned by means of the back gate voltage $V_g$. At high positive $V_g$ the devices feature transport…
We have performed microwave photoresistance measurements in high mobility GaAs/AlGaAs quantum wells and investigated the value of the effective mass. Surprisingly, the effective mass, obtained from the period of microwave-induced resistance…
The electric conductivity behavior in the single and double tunnel-coupled quantum wells (QW) with different doping profile caused by impact of short pulses of the strong longitudinal (in the quantum wells plane) electric field has been…
We calculate the single-particle states of a two-dimensional electron gas (2DEG) in a perpendicular quantizing magnetic field, which is periodic in one direction of the electron layer. We discuss the modulation of the electron density in…
Temperature-dependent reflectivity and photoluminescence spectra are studied for undoped ultra-wide 150 nm and 250 nm GaAs quantum wells. It is shown that spectral features previously attributed to a size quantization of exciton motion in…
We study the magneto-transport and magneto-electroluminescence properties of purely n-doped GaAs/Al$_{0.6}$Ga$_{0.4}$As resonant tunneling diodes with an In$_{0.15}$Ga$_{0.85}$As quantum well and emitter prewell. Before the resonant current…
Two-dimensional electron or hole systems in semiconductors offer the unique opportunity to investigate the physics of strongly interacting fermions. We have measured the 1/f resistance noise of two-dimensional hole systems in high mobility…