Title :
Coherent control of exciton density and spin
Author :
Heberle, Albert P. ; Baumberg, Jeremy J. ; Binder, Eberhard ; Kuhn, Tilmann ; Köhler, Klaus ; Ploog, Klaus H.
Author_Institution :
Hitachi Cambridge Lab., Cambridge, UK
fDate :
9/1/1996 12:00:00 AM
Abstract :
We demonstrate femtosecond coherent control of excitons in quantum wells with phase-locked pairs of 100 fs infrared pulses. Copolarized pump pulses allow coherent control of exciton density and coherent destruction of excitons within a few hundred femtoseconds of their creation. This technique thus promises to avoid speed penalties in devices associated with long-lived persistent carrier populations. Cross-polarized pump pulses allow coherent control of spin dynamics and conversion of unpolarized excitons into spin polarized ones. Carrier density and spin are determined, respectively, from the differential reflection and from the Faraday rotation of a third probe pulse. The experimental results are in good agreement with calculations based on the semiconductor Bloch equations
Keywords :
Faraday effect; carrier density; excitons; high-speed optical techniques; light coherence; light polarisation; semiconductor quantum wells; spin dynamics; 100 fs; Faraday rotation; carrier density; coherent control; coherent exciton destruction; copolarized pump pulses; cross-polarized pump pulses; exciton density; femtosecond coherent control; fs infrared pulses; long-lived persistent carrier populations; phase-locked pairs; probe pulse; quantum wells; semiconductor Bloch equations; speed penalties; spin; spin polarized excitons; unpolarized excitons; Excitons; Interference; Laser beams; Laser excitation; Optical pulses; Polarization; Probes; Pulse measurements; Pump lasers; Ultrafast optics;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.571778
