We demonstrate that electron-phonon interaction in quantum dots embedded in one-dimensional systems leads to pronounced, non-Markovian decoherence of optical transitions. The experiments that we present focus on the line shape of photoluminescence from low-temperature axially localized carbon nanotube excitons. The independent boson model that we use to model the phonon interactions reproduces ...

The electronic structure of the metallic Ti2O3 and insulating phases has been investigated using a combination of the three-dimensional periodic shell model and the discrete-variational (DV)-Xa cluster method. Besides the effects of intersite repulsive nearest-neighbor electron-electron (d-d) Coulombic interaction and the spin-spin interaction by means of a generalized Hubbard Hamiltonian, the ...

The matrix elements of the deformation potential of C 70 are calculated by means of a simple, yet accurate solution of the electron-phonon coupling problem in fullerenes, based on a parametrization of the ground state electronic density of the system in terms of sp 2+x hybridized orbitals. The value of the calculated dimensionless total electron-phonon coupling constant is λ ≈ 0.1, an order of ...

A strong electron-phonon interaction in a metal increases the electron density of states in the vicinity of the Fermi energy dramatically. This phenomenon is called electron-phonon mass enhancement. In this paper the question is investigated whether the mass enhancement can be manipulated in multi-layers of two metals with strong and weak electron-phonon interaction. A rich behavior is observed...

We develop a theory for the renormalization of the phonon energy dispersion in graphene due to the combined effects of both Coulomb and electron-phonon (e-ph) interactions. We obtain the renormalized phonon energy spectrum by an exact analytic derivation of the phonon self-energy, finding three distinct Kohn anomalies (KAs) at the phonon wave vector q=omega/v, 2k_{F}+/-omega/v for LO phonons an...

We study the Coulomb drag rate for electrons in a double-quantumwell st~ct~e taking into account the el~tron-optimal phon~n interactions. The full wave vector and frequency dependent random-phase approximation (RPA) at finite temperature is employed to describe the effective interlayer Coulomb interaction. The electron-electron and electron-optical phonon couplings are treated on an equal footi...

The Holstein Hubbard and Holstein t–J models are studied for a wide range of phonon frequencies, electron–electron and electron–phonon interaction strengths on finite lattices with up to ten sites by means of direct Lanczos diagonalization. Previously the necessary truncation of the phononic Hilbert space caused serious limitations to either very small systems (four or even two sites) or to wea...

Phonon-assisted singlet-singlet relaxation in semiconductor quantum dot molecules is studied theoretically. Laterally coupled quantum dot structures doped with two electrons are considered. We take into account interaction with acoustic phonon modes via deformation potential and piezoelectric coupling. We show that piezoelectric mechanism for the considered system is of great importance and for...

Recent scanning tunneling spectroscopy experiments on graphene reported an unexpected gap of about +/-60 meV around the Fermi level [V. W. Brar, Appl. Phys. Lett. 91, 122102 (2007); 10.1063/1.2771084Y. Zhang, Nature Phys. 4, 627 (2008)10.1038/nphys1022]. Here we give a theoretical investigation explaining the experimentally observed spectra and confirming the phonon-mediated tunneling as the re...

Heat dissipation in current-carrying cryogenic nanostructures is problematic because the phonon density of states decreases strongly as energy decreases. We show that the Coulomb interaction can prove a valuable resource for carrier cooling via coupling to a nearby cold electron reservoir. Specifically, we consider the geometry of an electron bilayer in a silicon-based heterostructure and analy...