Charge separation of dense two-dimensional electron-hole gases: mechanism for exciton ring pattern formation.
We report on new experiments and theory that unambiguously resolve the recent puzzling observation of large diameter exciton emission halos around a laser excitation spot in two dimensional systems. We find a novel separation of plasmas of opposite charge with emission from the sharp circular boundary between these two regions. This charge separation allows for cooling of initially hot optically generated carriers as they dwell in the charge reservoirs for very long times.
Rapaport
R
R
Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974, USA.
Chen
Gang
G
Snoke
D
D
Simon
Steven H
SH
Pfeiffer
Loren
L
West
Ken
K
Liu
Y
Y
Denev
S
S