ISBN 978-3-8439-2312-5

978-3-8439-2312-5, Reihe Physik

Wolf Wüster
Cavity quantum electrodynamics with many-body states of a two-dimensional electron system

141 Seiten, Dissertation Eidgenössische Technische Hochschule (ETH) Zürich (2015), Softcover, B5

Zusammenfassung / Abstract

We combine the physics of correlated many-body states of a two-dimensional electron system with the methods of cavity quantum electrodynamics. By coupling the cavity photon of an AlGaAs based DBR micro-cavity structure to optical inter-band excitations of a 20 nm GaAs quantum well we observe the emergence of novel many-body polariton modes. In the absence of a magnetic field we find Fermi-edge polaritons and provide a new interpretation of these modes as optical many-body excitations at the Fermi-edge that are strongly coupled to the cavity photon. In presence of a magnetic field we use the strong coupling of the cavity mode to bound trion states of inter Landau level transitions as a new spectroscopic tool to study correlated states in the integer and fractional quantum Hall regime. These quantum Hall polaritons provide a direct way to study the spin-polarization of quantum Hall states by measuring the polarization dependent normal-mode splitting. We think that our technique is also suited to study the compressibility of the electron system and therefore constitutes a powerful method to complement transport spectroscopy with the advantages of a minimally invasive local probe.