A comprehensive picture of polaron and bipolaron physics is essential to understand the
optical absorption spectrum in many materials with electron-phonon interactions. In …

The optical-conductivity profile carries information on electronic dynamics in interacting
quantum many-body systems. Its computation is a formidable task that is usually …

We examine the range of validity of the second-order cumulant expansion (CE) for the
calculation of spectral functions, quasiparticle properties, and mobility of the Holstein …

Numerically “exact” methods addressing the dynamics of coupled electron–phonon systems
have been intensively developed. Nevertheless, the corresponding results for the electron …

In the context of a single-electron two orbital Holstein system coupled to dispersionless
bosons, we develop a general method to correct the single-particle Green's function using a …

Previously, we introduced a method for systematically correcting a quasiparticle green's
function via a power series expansion. Here we present an ODE based formalisms of power …

In this work, we investigate the ability of the cumulant expansion (CE) to capture one-particle
spectral information in electron-phonon coupled systems at both zero and finite …

Cavity exciton-polaritons exhibit ballistic transport and can achieve a distance of 100$\mu $
m in one picosecond. This ballistic transport significantly enhances mobility compared to that …

In this thesis we develop methods for many-body open quantum systems and apply them to
systems of organic polaritons. The methods employ a mean-field approach to reduce the …

Electron-phonon interactions (EPIs) are ubiquitous in condensed matter physics and
materials science. They are crucial for understanding numerous phenomena, including …