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Composite fermions with a warped Fermi contour.
M A Mueed1, D Kamburov1, Yang Liu1
1Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Physical Review Letters
|May 16, 2015
Summary
Measurements reveal that the Fermi contour of composite fermions is shaped by the Landau level characteristics. Specifically, warping in the hole band leads to a warped composite fermion Fermi contour.
Area of Science:
- Condensed Matter Physics
- Quantum Hall Effect Studies
Background:
- Composite fermions emerge as quasiparticles in two-dimensional electron systems.
- Understanding their properties is crucial for exploring novel quantum states.
Purpose of the Study:
- To investigate the Fermi contour shape of hole-flux composite fermions.
- To determine the influence of Landau level characteristics on composite fermion behavior.
Main Methods:
- Measurements of commensurability features near the Landau filling factor ν=1/2.
- Utilizing a wide GaAs quantum well for confinement.
Main Results:
- The Fermi contour of composite fermions is strongly influenced by the originating Landau level.
- A warped Fermi contour is observed when the Landau level originates from a hole band with significant warping.
Conclusions:
- The shape of the composite fermion Fermi contour is directly linked to the band structure of the parent Landau level.
- This highlights the importance of Landau level topology in determining emergent quasiparticle properties.
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