Dephasing time of composite fermions
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239 (United States)
- NORDITA, Blegdamsvej 17, DK-2100 Copenhagen O/ (Denmark)
- O/rsted Laboratory, H. C. O/rsted Institute, Universitetsparken 5, University of Copenhagen, DK-2100 Copenhagen O/ (Denmark)
We study the dephasing of fermions interacting with a fluctuating transverse-gauge field. The divergence of the imaginary part of the fermion self-energy at finite temperatures is shown to result from a breakdown of Fermi{close_quote}s golden rule due to a faster than exponential decay in time. The strong dephasing affects experiments where phase coherence is probed. This result is used to describe the suppression of Shubnikov{endash}de Haas (SdH) oscillations of composite fermions (oscillations in the conductivity near the half-filled Landau level). We find that it is important to take into account both the effect of dephasing and the mass renormalization. We conclude that while it is possible to use the conventional theory to extract an effective mass from the temperature dependence of the SdH oscillations, the resulting effective mass differs from the {ital m}{sup {asterisk}} of the quasiparticle in Fermi-liquid theory. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 383825
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 54, Issue 12; Other Information: PBD: Sep 1996
- Country of Publication:
- United States
- Language:
- English
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