Collective electronic excitation in a trapped ensemble of photogenerated dipolar excitons and free holes revealed by inelastic light scattering
arXiv:1612.04072 · doi:10.1103/PhysRevB.95.085312
Abstract
Photogenerated excitonic ensembles confined in coupled GaAs quantum wells are probed by a complementary approach of emission spectroscopy and resonant inelastic light scattering. Lateral electrostatic trap geometries are used to create dense systems of spatially indirect excitons and excess holes with similar densities in the order of 10 cm. Inelastic light scattering spectra reveal a very sharp low-lying collective mode that is identified at an energy of 0.44 meV and a FWHM of only ~50 eV. This mode is interpreted as a plasmon excitation of the excess hole system coupled to the photogenerated indirect excitons. The emission energy of the indirect excitons shifts under the application of a perpendicular applied electric field with the quantum-confined Stark effect unperturbed from the presence of free charge carriers. Our results illustrate the potential of studying low-lying collective excitations in photogenerated exciton systems to explore the many-body phase diagram, related phase transitions, and interaction physics.
arXiv comment19 pages, 5 figures
References in corpus (30)
- Bose-Einstein Condensation of Excitons in Bilayer Electron Systems
- High-temperature superfluidity with indirect excitons in van der Waals heterostructures
- Spontaneous Coherence in a Cold Exciton Gas
- Counterflow measurements in strongly correlated GaAs hole bilayers: evidence for electron-hole pairing
- Excitonic superfluid phase in Double Bilayer Graphene
- Exciton Condensation and Perfect Coulomb Drag
- Analysis of the exciton-exciton interaction in semiconductor quantum wells
- Bose-Einstein condensation in semiconductors: the key role of dark excitons
- Activated Transport in the individual Layers that form the =1 Exciton Condensate
- Electron-hole pairing in graphene-GaAs heterostructures
- Bose-Einstein statistics in thermalization and photoluminescence of quantum well excitons
- Evidence for a Bose-Einstein condensate of excitons
- Exciton Liquid in Coupled Quantum Wells
- Observation of Collective Excitations of the Dilute 2D Electron System
- Resonant Raman scattering by elementary electronic excitations in semiconductor structures
- Micropatterned Electrostatic Traps for Indirect Excitons in Coupled GaAs Quantum Wells
- Coherence and Optical Emission from Bilayer Exciton Condensates
- A dark incompressible dipolar liquid of excitons
- Predicting the Ionization Threshold for Carriers in Excited Semiconductors
- Roton confinement in trapped dipolar Bose-Einstein condensates
- Comment on "Photoluminescence ring formation in coupled quantum wells: Excitonic versus ambipolar diffusion"
- Correlations in a two-dimensional Bose gas with long range interactions
- Exciton condensates in semiconductor quantum wells emit coherent light
- Observation of non-conventional spin waves in composite fermion ferromagnets
- Roton-maxon spectrum and instability for weakly interacting dipolar excitons in a semiconductor layer
- Observation of soft magnetorotons in bilayer quantum Hall ferromagnets
- Forming and confining of dipolar excitons by quantizing magnetic fields
- Gapped Excitations of unconventional FQHE states in the Second Landau Level
- Optical emission spectroscopy study of competing phases of electrons in the second Landau level
- Confocal shift interferometry of coherent emission from trapped dipolar excitons