The research carried out in the group is at the intersection of quantum optics and mesoscopic condensed matter physics. We implement various quantum optical measurement techniques to carry out optical spectroscopy and/or coherent manipulation of solid-state emitters. We are particularly interested in quantum dots, quantum well cavity-polaritons, quantum hall systems, carbon graphene and nanotubes-like systems, which typically show rich physics due to the system-environment coupling.
Part of our activities are based on control and manipulation of isolated quantum systems by coupling them to high-finesse cavities and coherent laser fields. Specific projects that fall into this category include the generation of entanglement between two distant spins, the realization of decoherence-free spin qubits, and the implementation of strong photon-photon interactions by coupling quantum emitters to nano-scale optical cavities. These experiments parallel more traditional quantum optics experiments based on single atoms or ions. Remarkably, the rich environment of the solid-state emitters provides new challenges and fascinating puzzles.
A second complementary line of research in the group aims at using optical spectroscopy to study strongly correlated condensed-matter systems. The system-environment coupling that leads to unwanted decoherence for applications in quantum information processing, emerges as a source of exciting many-body phenomena when the emitter(s) are designed to interact strongly with the environmental degrees of freedom, such as a nuclear spin ensemble or a nearby degenerate electron gas. Of particular interest to us are the quantum impurity system and the central-spin model that allow for a natural realization in semiconductor quantum dots. In contrast to transport spectroscopy, optical excitation in these model systems typically realize a quantum quench, which in turn allows for the investigation of non-equilibrium dynamics.