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Spin currents in a coherent exciton gas
A A High1, A T Hammack1, J R Leonard1
1Department of Physics, University of California at San Diego, La Jolla, California 92093-0319, USA.
Physical Review Letters
|August 29, 2014
Summary
We observed spin currents in a coherent gas of indirect excitons, a novel mechanism that suppresses spin relaxation and creates diverse polarization patterns. These spin currents can be controlled by magnetic fields.
Area of Science:
- Condensed matter physics
- Quantum optics
- Materials science
Background:
- Indirect excitons are crucial for quantum information processing.
- Spin relaxation limits the efficiency of spin-based devices.
- Coherent phenomena in excitonic systems are of great interest.
Purpose of the Study:
- To investigate the formation and properties of spin currents in coherent exciton gases.
- To explore a new mechanism for spin relaxation suppression.
- To understand the control and theoretical description of exciton spin transport.
Main Methods:
- Observation of spin currents in a coherent gas of indirect excitons.
- Analysis of various polarization patterns (helical, four-leaf, spiral, bell, periodic).
- Application of magnetic fields to control spin currents.
- Development of a theoretical model for coherent exciton spin transport.
Main Results:
- Demonstrated long-range spin currents originating from coherent bosonic pairs.
- Identified a new mechanism suppressing spin relaxation.
- Observed diverse polarization patterns resulting from spin currents.
- Showcased magnetic field control over spin currents.
Conclusions:
- Coherent exciton gases provide a platform for long-range spin transport.
- The formation of coherent bosonic pairs effectively suppresses spin relaxation.
- Exciton spin transport exhibits complex patterns controllable by external fields.
- The developed theory accurately describes observed phenomena and spin current trajectories.
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