Abstract
Coulomb-mediated interactions between intersubband excitations of electrons in double quantum wells and longitudinal optical phonons are studied by two-dimensional spectroscopy in the terahertz frequency range. The multitude of diagonal and off-diagonal peaks in the 2D spectrum gives evidence of strong polaronic signatures in the nonlinear response. A quantitative theoretical analysis reveals a dipole coupling of electrons to the polar lattice that is much stronger than in bulk GaAs, due to a dynamic localization of the electron wave function by scattering processes.
- Received 7 January 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.067401
© 2011 American Physical Society