Coherence and recombination dynamics in semiconducting nanostructures

点击翻译按钮获取中文摘要

When a semiconductor absorbs a photon, an electron is excited to the conduction band, leaving a hole in the valence band. The Coulomb interaction between electrons and holes results in a bound state, the exciton, which controls to a large extent the optical properties of semiconductors. When the semiconductors are structured on a nanometric scale, the exciton optical response is dramatically altered by quantum confinement, localisation and delocalisation processes, exchange interaction and other many-body effects.******My research program is about probing exciton dynamics in the complex energy landscape associated with nanostructures in order to understand how energy is absorbed and redistributed within a collective excitation picture. This issue, which is arguably amongst one of the most exciting in contemporary condensed-matter physics, involves many-body physics within and beyond the perturbative regime. It is also integral to excitonics, which deals with applications, ranging from efficient light emitters to quantum logical devices, where the specific properties of excitons are exploited.******The main thrust of my activities is directed towards the two following systems:******- Exciton localisation and recombination in InGaN/GaN nanowires.***- Extreme excitons in two-dimensional van der Waals semiconductor heterostructures.******These projects involve materials or systems of high potential technological impact, but where the fundamental processes that control exciton creation, relaxation and recombination are imperfectly, if at all, understood. They thus constitute excellent test beds for strongly correlated electron theories.