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Quantum Hall exciton condensation at full spin polarization
A D K Finck1, J P Eisenstein, L N Pfeiffer
1Condensed Matter Physics, California Institute of Technology, Pasadena, California 91125, USA.
Physical Review Letters
|April 7, 2010
Summary
Investigating quantum Hall bilayers, this study reveals how Zeeman energy impacts excitonic phase transitions. The critical layer separation initially rises with Zeeman energy before declining, with wider transitions observed at higher energies.
Area of Science:
- Condensed Matter Physics
- Quantum Hall Effect
- Excitonic Phases
Background:
- Quantum Hall bilayers exhibit complex electronic phases.
- Exciton condensation is a key phenomenon in these systems.
- Zeeman energy's role in tuning these phases requires further investigation.
Purpose of the Study:
- To probe the excitonic phase transition in quantum Hall bilayers at total filling factor nu(T) = 1.
- To investigate the influence of Zeeman energy (E(Z)) on the critical layer separation and transition width.
Main Methods:
- Utilizing Coulomb drag measurements as a sensitive probe.
- Systematically varying Zeeman energy and layer separation (d/l).
Main Results:
- The critical layer separation (d/l)(c) for exciton condensation increases with E(Z) initially, then decreases.
- At high E(Z), the transition width broadens significantly and persists to zero temperature.
- Observed phenomena are analyzed within models of mixed-fluid systems.
Conclusions:
- Zeeman energy plays a crucial role in modulating the excitonic phase transition in quantum Hall bilayers.
- The observed transition broadening at high E(Z) suggests complex interplay between spin polarization and exciton condensation.
- Results provide insights into the nature of correlated electron fluids in two-dimensional systems.
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