Efficient signal communication uses photons. Signal processing, however, an optically inactive medium, electrons. Therefore, interconnection between electronic processing and optical is required at the integrated circuit level. We demonstrated control of exciton fluxes in excitonic circuit. The consists three optoelectronic transistors performs operations with fluxes, such as directional switching merging. Photons transform into excitons input, photons output. flux from input to output...

The photoluminescence of excitons confined in an electric field tunable coupled AlAs/GaAs quantum well has been investigated at $T\ensuremath{\ge}350$ mK and magnetic fields $H\ensuremath{\le}14$ T. In the indirect regime where electrons holes are separated both real $k$ space, was found to result (i) a strong change intensity decay time which is attributed anomalies exciton transport (ii) appearance huge broad band noise evidence for condensation.

We report about optical experiments on electric field tunable AlAs/GaAs coupled quantum well structures in the regime of induced \ensuremath{\Gamma}-X transition. Using energetically X-point state AlAs layer as an internal energy spectrometer and charge reservoir we are able to map out electronic states neighboring GaAs great detail. In spatially resolved bias voltage dependent photoluminescence find sets extremely narrow emission lines below fundamental band gap well. The new shown...

We observe and analyze strongly nonlinear photoluminescence kinetics of indirect excitons in GaAs/AlGaAs coupled quantum wells at low bath temperatures, > or = 50 mK. The long recombination lifetime promotes accumulation these Bose particles the lowest energy states allows photoexcited to cool down temperatures where dilute 2D gas becomes statistically degenerate. Our main result--a strong enhancement exciton scattering rate low-energy with increasing concentration excitons--reveals bosonic...

Indirect excitons (IXs) in van der Waals transition-metal dichalcogenide (TMD) heterostructures are characterized by a high binding energy making them stable at room temperature and giving the opportunity for exploring fundamental phenomena excitonic systems developing devices operational temperatures. We present observation of IXs TMD based on monolayers MoS$_2$ separated atomically thin hexagonal boron nitride. The realized heterostructure have lifetimes orders magnitude longer than direct...

Condensation is observed in a gas of indirect excitons confined an electrostatic trap. Imaging and interferometric measurements detect that condense at the trap bottom exciton spontaneous coherence emerges with lowering temperature. Below temperature about 1 K, direct signature Bose–Einstein condensation, extension over entire cloud, observed.

Indirect excitons (IX) in semiconductor heterostructures are bosons, which can cool below the temperature of quantum degeneracy and be effectively controlled by voltage light. IX Bose gases devices were explored GaAs where an range existence is limited to low temperatures due binding energies. IXs van der Waals transition-metal dichalcogenide (TMD) characterized large energies giving opportunity for exploring excitonic creating at high temperatures. TMD also offer a new platform studying...

Due to the long lifetime of indirect (interwell) excitons, exciton condensation (analogous Bose-Einstein bosons) is expected occur in coupled quantum wells (CQW's). The critical conditions for have been predicted be strongly improved by high magnetic field perpendicular well plane. We present results experimental study transport and photoluminescence excitons AlAs/GaAs CQW's at low temperatures $(T>~350$ mK) fields $(B<~14$ T). Strong anomalies luminescence observed fields: a large increase...

Bound electron?hole pairs?excitons?are light Bose particles with a mass comparable to or smaller than that of the free electron. Since quantum degeneracy temperature scales inversely mass, it is anticipated Bose?Einstein condensation an exciton gas can be achieved at temperatures about 1?K, orders magnitude larger micro-Kelvin employed in atomic condensation. High and possibility control density by laser photoexcitation make cold excitons model system for studies collective states many-body...

The dependence of the intersubband absorption line shape on subband dispersion and Coulomb interaction between electrons is studied using Hartree-Fock semiconductor Bloch equations. For subbands with same effective masses, we show that absorption/emission solely determined by single-electron properties. very different results in a strong redistribution oscillator strength. this limit Fermi-edge collective mode induced repelling electron-hole pair.

We present a theoretical and experimental investigation of the effects magnetic field on quasi-two-dimensional excitons. calculate internal structures dispersion relations spatially direct indirect excitons in single coupled quantum wells perpendicular to well plane. find sharp transition from hydrogenlike exciton magnetoexciton with increasing center-of-mass momentum at fixed weak field. At that mean electron-hole separation increases sharply becomes...

The macroscopic rings observed in the photoluminescence patterns of excitons coupled quantum wells are explained by a mechanism carrier imbalance, transport, and recombination. originate from spatial separation $p$ $n$ carriers, occur at interface domains, where generated. We explore states ring over range temperatures down to $380\text{ }\mathrm{mK}$ report transition into periodic array aggregates, new low-temperature ordered exciton state.

We demonstrate experimental proof of principle for an optoelectronic transistor based on the modulation exciton flux via gate voltage. The (EXOT) implements electronic operation photons by using excitons as intermediate media; intensity light emitted at optical output is proportional to input and controlled electronically gate. a contrast ratio 30 between state off EXOT its speeds greater than 1 GHz. Our studies also high-speed control both potential energy time scale much shorter lifetime.

We study transport of indirect excitons in $\mathrm{GaAs}/\mathrm{AlGaAs}$ coupled quantum wells linear lattices created by laterally modulated gate voltage. The localization-delocalization transition for across the lattice was observed with reducing amplitude or increasing exciton density. interaction energy at is close to amplitude. These results are consistent model, which attributes interaction-induced percolation gas through external potential. also discuss applications potentials...

We report on the observation of a spin texture in cold exciton gas GaAs/AlGaAs coupled quantum well structure. The is observed around rings. phenomena include: ring linear polarization, vortex polarization with perpendicular to radial direction, an anisotropy flux, skew fluxes orthogonal circular polarizations and corresponding four-leaf pattern periodic texture, extended coherence region vortex. data indicate transport regime where locked direction particle propagation scattering suppressed.

A Mach-Zehnder interferometer with spatial and spectral resolution was used to probe spontaneous coherence in cold exciton gases, which are implemented experimentally the ring of indirect excitons coupled quantum wells. strong enhancement length is observed at temperatures below a few Kelvin. The increase correlated macroscopic ordering excitons.

Optical trapping and manipulation of neutral particles has led to a variety experiments from stretching DNA-molecules cooling atoms. An exciting recent outgrowth the technique is an experimental implementation atom Bose-Einstein condensation. In this paper, we propose demonstrate laser induced for new system--a gas excitons in quantum well structures. We report on highly degenerate Bose traps.

We consider in-plane electrostatic traps for indirect excitons in coupled quantum wells, where the are formed by a laterally modulated gate voltage. An intrinsic obstacle exciton confinement is an electric field that can lead to dissociation. propose design suppress and, at same time, effectively confine traps. present calculations various classes of and experimental proof principle trapping