# Program

# Solid-state Quantum Optics

**Atac Imamoglu (Institute of Quantum Electronics, ETH Zürich, Zürich, Switzerland)**

In the first lecture, I will focus on quantum optics experiments based on zero-dimensional solid-state quantum emitters where the goal is the generation of heralded entanglement between distant qubits. The focus will be on generation of heralded quantum entanglement between two semiconductor quantum dot spins separated by more than five meters. The efficient spin-photon interface provided by self-assembled quantum dots allowed us to reach an unprecedented rate of 2300 entangled spin pairs per second, which represents an improvement of three orders of magnitude as compared to prior experiments in other physical systems.

In the second lecture, I will describe the properties of transition metal dichalcogenide (TMD) monolayers, such as molybdenum diselenide (MoSe2), which represent a new class of valley semiconductors exhibiting novel features such as strong Coulomb interactions, finite exciton Berry curvature with novel optical signatures and locking of spin and valley degrees of freedom due to large spin-orbit coupling. In contrast to quantum wells or two-dimensional electron systems in III-V semiconductors, TMD monolayers exhibit an ultra-large exciton binding energy of order 500 meV and strong trion peaks in photoluminescence that are red-shifted from the exciton line by 30 meV. The focus of this lecture will be on cavity spectroscopy of gate-tunable monolayer MoSe2 exhibiting strong exciton-electron interactions, as well as non-perturbative coupling of excitons to a single microcavity. Optical creation of an exciton or a polariton in a two-dimensional electron system in a TMD monolayer embedded in a microcavity constitutes a new frontier for Fermi-polaron physics due to an interplay between cavity-coupling favoring ultra-low mass polariton formation and exciton-electron interactions leading to polaron or trion formation. As we increase the electron density, we observe that the oscillator strength, as determined from the observed normal-mode-splitting, is transferred from the repulsive-exciton branch to the lower energy attractive-exciton-polaron. Our findings constitute a first step in investigation of a new class of degenerate Bose-Fermi mixtures consisting of polaritons and electrons.