Related papers: Exciton Liquid in Coupled Quantum Wells
We study the exciton gas-liquid transition in GaAs/AlGaAs coupled quantum wells. Below a critical temperature, Tc=4.8K, and above a threshold laser power density the system undergoes a phase transition into a liquid state. We determine the…
We study spatially indirect excitons of GaAs quantum wells, confined in a 10 microns electrostatic trap. Below a critical temperature of about 1 Kelvin, we detect macroscopic spatial coherence and quantised vortices in the weak…
We show that a quasi-two dimensional condensate of optically active excitons emits coherent light even in the absence of population inversion. This allows an unambiguous and clear experimental detection of the condensed phase. We prove…
We report on the strong coupling between inorganic quantum well excitons and surface plasmons. For that purpose a corrugated silver film was deposited on the top of a heterostructure consisting of GaAs/GaAlAs quantum wells. The formation of…
The region surrounding the excitonic insulator phase is a three-component plasma composed of electrons, holes, and excitons. Due to the extended nature of the excitons, their presence influences the surrounding electrons and holes. We…
When electron-hole pairs are excited in a semiconductor, it is a priori not clear if they form a fermionic plasma of unbound particles or a bosonic exciton gas. Usually, the exciton phase is associated with low temperatures. In atomically…
We investigate resonant photoluminescence arising from incompressible quantum liquids formed in two-dimensional electron systems. We demonstrate that, for excitons composed of a photoexcited electron occupying the upper spin sublevel of the…
Excitons in semiconductors are usually non interacting and behave like an ideal gas, but may condense to a strongly correlated liquid like state, i.e. electron hole liquid (EHL), at high density and appropriate temperature. EHL is a…
The bound electron-hole pairs known as excitons govern the optical properties of insulating solids. While their behavior in equilibrium is well-understood theoretically, the nonequilibrium regime at high excitation densities-where phenomena…
Time-resolved photoluminescence spectra after nonresonant excitation show a distinct 1s resonance, independent of the existence of bound excitons. A microscopic analysis identifies excitonic and electron-hole plasma contributions. For low…
Long-lived indirect excitons (IXs) exhibit a rich phase diagram, including a Bose-Einstein condensate (BEC), a Wigner crystal, and other exotic phases. Recent experiments have hinted at a new, "classical" liquid of IXs above the BEC…
Many-component electron-hole plasma is considered in the Coupled Quantum Wells (CQW). It is found that the homogeneous state of the plasma is unstable if the carrier density is sufficiently small. The instability results in the breakdown…
The photoluminescence (PL) of a two-dimensional electron gas (2DEG) in a high magnetic field is studied as a function of the filling factor and the separation d between the electron layer and the valence hole. Depending on the magnitude of…
Excitons are pairs of electrons and holes bound together by the Coulomb interaction. At low temperatures, excitons can form a Bose-Einstein condensate (BEC), enabling macroscopic phase coherence and superfluidity. An electronic double layer…
Photoluminescence (PL) and reflectivity spectra of a high-quality InGaAs/GaAs quantum well structure reveal a series of ultra-narrow peaks attributed to the quantum confined exciton states. The intensity of these peaks decreases as a…
Excitons are spin integer particles that are predicted to condense into a coherent quantum state at sufficiently low temperature, and exciton condensates can be realized at much higher temperature than condensates of atoms because of strong…
In this paper we present a study of an exciton system where electrons and holes are confined in double quantum well structures. The dominating interaction between excitons in such systems is a dipole - dipole repulsion. We show that the…
Photoluminescence (PL) has been used to study two-dimensional incompressible electron liquids in high magnetic fields for nearly two decades. However, some of the observed anomalies coincident with the fractional quantum Hall effect are…
Optically generated electron-hole pairs can probe strongly correlated electronic matter, or, by forming exciton-polaritons within an optical cavity, give rise to photonic nonlinearities. The present paper theoretically studies the…
We have studied the collective properties of two-dimensional (2D) excitons immersed within a quantum well which contains 2D excitons and a two-dimensional electron gas (2DEG). We have also analyzed the excitations for a system of 2D dipole…