Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2005-06-16
Phys. Rev. B 62, 7336 (2000)
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
8 pages, 4 figures
Scientific paper
10.1103/PhysRevB.62.7336
The relaxation of electrons in quantum dots via phonon emission is hindered by the discrete nature of the dot levels (phonon bottleneck). In order to clarify the issue theoretically we consider a system of $N$ discrete fermionic states (dot levels) coupled to an unlimited number of bosonic modes with the same energy (dispersionless phonons). In analogy to the Gram-Schmidt orthogonalization procedure, we perform a unitary transformation into new bosonic modes. Since only $N(N+1)/2$ of them couple to the fermions, a numerically exact treatment is possible. The formalism is applied to a GaAs quantum dot with only two electronic levels. If close to resonance with the phonon energy, the electronic transition shows a splitting due to quantum mechanical level repulsion. This is driven mainly by one bosonic mode, whereas the other two provide further polaronic renormalizations. The numerically exact results for the electron spectral function compare favourably with an analytic solution based on degenerate perturbation theory in the basis of shifted oscillator states. In contrast, the widely used selfconsistent first-order Born approximation proves insufficient in describing the rich spectral features.
Castella Herve
Stauber Tobias
Zimmermann Rainer
No associations
LandOfFree
Electron-Phonon Interacation in Quantum Dots: A Solvable Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Electron-Phonon Interacation in Quantum Dots: A Solvable Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron-Phonon Interacation in Quantum Dots: A Solvable Model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-4727