The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) theory within second quantization representation of the Fock space, a novel numerically exact methodology to treat many-body quantum dynamics for systems containing identical particles, is applied to study the effect of vibrational motion on electron transport in a generic model for single-molecule junctions. The results demons...

The standard polaron band model of doped organic semiconductors predicts that density-of-states shift into the π-π* gap to give a partially filled polaron band that pins the Fermi level. This picture neglects both Madelung and Hubbard interactions. Here we show using ultrahigh workfunction hole-doped model triarylamine-fluorene copolymers that Hubbard interaction strongly splits the singly-occu...

We report magnetoresistivity measurements on a La1:2Sr1:8Mn2O7 single crystal. The charge transport in the ferromagnetic phase is dominated by two-magnon scattering in the high T range and by weak localization effects at lower T ; in the non-metallic regime. In the paramagnetic phase, rabðTÞ obeys the adiabatic small polaron hopping mechanism, while rcðTÞ follows an Arrhenius behavior with the ...

We measure radio-frequency spectra for a two-component mixture of a 6Li atomic Fermi gas in a quasi-two-dimensional regime with the Fermi energy comparable to the energy level spacing in the tightly confining potential. Near the Feshbach resonance, we find that the observed resonances do not correspond to transitions between confinement-induced dimers. The spectral shifts can be fit by assuming...

We study the generalization of the spin-boson model to spins greater than one-half in the strong-coupling regime. This model applies to dissipative large spins as well as to ensembles of identical two-state systems coupled to a common environment. Using a combination of polaron transformations and master equations, we find nonexponential spin relaxation towards one of two possible equilibrium s...

We present a study of the one dimensional Su-Schrieffer-Heeger model Hamiltonian by a diagrammatic perturbative method in the weak electron-phonon coupling regime. Exact computation of both the charge carrier effective mass and the electron spectral function shows that electrons are good quasiparticles in the adiabatic and antiadiabatic limits but novel features emerge in the intermediate regim...

When an impurity interacts with a bath of phonons it forms a polaron. For increasing interaction strengths the mass of the polaron increases and it can become self-trapped. For impurity atoms inside an atomic Bose-Einstein condensate (BEC) the nature of this transition is not understood. While Feynman's variational approach to the Fröhlich model predicts a sharp transition for light impurities,...

This thesis presents experiments investigating the phase diagram of ultracold atomic Fermi gases using radio-frequency spectroscopy. The tunability of many experimental parameters including the temperature, the interparticle interaction strength and the relative population of different fermions allows to access very different physical regimes. Radio-frequency spectroscopy has been developed int...

Recent studies have demonstrated that higher than two-body bath-impurity correlations are not important for quantitatively describing the ground state of Bose polaron. Motivated by above, we employ so-called Gross Ansatz (GA) approach to unravel stationary and dynamical properties homogeneous one-dimensional Bose-polaron different impurity momenta couplings. We explicate character equilibrium c...