Qi Zhang, Takashi Arikawa, Eiji Kato, John L. Reno, Wei Pan, John D. Watson, Michael J. Manfra, Michael A. Zudov, Mikhail Tokman, Maria Erukhimova, Alexey Belyanin, and Junichiro Kono
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.047601
We report on the observation of collective radiative decay, or superradiance, of cyclotron resonance (CR) in high-mobility two-dimensional electron gases in GaAs quantum wells using time-domain terahertz magnetospectroscopy. The decay rate of coherent CR oscillations increases linearly with the electron density in a wide range, which is a hallmark of superradiant damping. Our fully quantum mechanical theory provides a universal formula for the decay rate, which reproduces our experimental data without any adjustable parameter. These results firmly establish the many-body nature of CR decoherence in this system, despite the fact that the CR frequency is immune to electron-electron interactions due to Kohn’s theorem.
DOI: http://dx.doi.org/10.1103/PhysRevLett.113.047601
© 2014 American Physical Society
No comments:
Post a Comment