Abstract
We consider transport through finite quantum systems such as quantum barriers, wells, dots, and junctions, coupled to local vibrational modes in the quantal regime. As a generic model, we study the Holstein-Hubbard Hamiltonian with site-dependent potentials and interactions. Depending on the barrier height to electron-phonon coupling strength ratio and the phonon frequency, we find distinctly opposed behaviors: vibration-mediated tunneling or intrinsic localization of (bi)polarons. These regimes are strongly manifested in the density correlations, mobility, and optical response calculated by exact numerical techniques.
1 More- Received 17 October 2007
DOI:https://doi.org/10.1103/PhysRevB.77.085117
©2008 American Physical Society