Nonequilibrium Dynamics Beyond Dephasing

Cold atomic gases trapped and manipulated on atom chips allow the realization of seminal one-dimensional (1d) quantum many-body problems in an isolated and well controlled environment. In this context, this thesis presents an extensive experimental study of non-equilibrium dynamics in 1d Bose gases, with a focus on processes that go beyond simple dephasing dynamics. It reports on the observation of recurrences of coherence in the post-quench dynamics of a pair of 1d Bose gases and presents a detailed study of their decay.

This thesis sheds light on the unique dynamics of optoelectronic devices based on semiconductor quantum-dots. The complex scattering processes involved in filling the optically active quantum-dot states and the presence of charge-carrier nonequilibrium conditions are identified as sources for the distinct dynamical behavior of quantum-dot based devices. Comprehensive theoretical models, which allow for an accurate description of such devices, are presented and applied to recent experimental observations. The low sensitivity of quantum-dot lasers to optical perturbations is directly attributed to their unique charge-carrier dynamics and amplitude-phase-coupling, which is found not to be accurately described by conventional approaches. The potential of quantum-dot semiconductor optical amplifiers for novel applications such as simultaneous multi-state amplification, ultra-wide wavelength conversion, and coherent pulse shaping is investigated. The scattering mechanisms and the unique electronic structure of semiconductor quantum-dots are found to make such devices prime candidates for the implementation of next-generation optoelectronic applications, which could significantly simplify optical telecommunication networks and open up novel high-speed data transmission schemes.

This book studies the dynamics of fundamental collective excitations in quantum materials, focusing on the use of state-of-the-art ultrafast broadband optical spectroscopy. Collective behaviour in solids lies at the origin of several cooperative phenomena that can lead to profound transformations, instabilities and phase transitions. Revealing the dynamics of collective excitations is a topic of pivotal importance in contemporary condensed matter physics, as it provides information on the strength and spatial distribution of interactions and correlation.

This book studies the dynamics of fundamental collective excitations in quantum materials, focusing on the use of state-of-the-art ultrafast broadband optical spectroscopy. Collective behaviour in solids lies at the origin of several cooperative phenomena that can lead to profound transformations, instabilities and phase transitions. Revealing the dynamics of collective excitations is a topic of pivotal importance in contemporary condensed matter physics, as it provides information on the strength and spatial distribution of interactions and correlation.

This book studies the dynamics of fundamental collective excitations in quantum materials, focusing on the use of state-of-the-art ultrafast broadband optical spectroscopy. Collective behaviour in solids lies at the origin of several cooperative phenomena that can lead to profound transformations, instabilities and phase transitions. Revealing the dynamics of collective excitations is a topic of pivotal importance in contemporary condensed matter physics, as it provides information on the strength and spatial distribution of interactions and correlation.

This book studies the dynamics of fundamental collective excitations in quantum materials, focusing on the use of state-of-the-art ultrafast broadband optical spectroscopy. Collective behaviour in solids lies at the origin of several cooperative phenomena that can lead to profound transformations, instabilities and phase transitions. Revealing the dynamics of collective excitations is a topic of pivotal importance in contemporary condensed matter physics, as it provides information on the strength and spatial distribution of interactions and correlation.