Quantum Optics of Collective Emission and Structured Photonic Environments

Quantum optics provides both the fundamental framework for understanding light–matter interactions and the physical platform for quantum technologies such as quantum communication, computation, and sensing. Central to these applications is the generation and control of multiphoton states and their nonclassical correlations. At their core, all photonic quantum states are created through spontaneous emission, the fundamental quantum-mechanical process that lies at the heart of quantum optics. Understanding and controlling spontaneous emission—through collective interactions and structured photonic environments—is therefore essential for realizing desired multiphoton states.

In this seminar, I will show how collective spontaneous emission can be harnessed to generate and control quantum light. By exploring multi-emitter dynamics, I demonstrate how different entangled multiphoton states can be produced through distinct emitter coupling schemes, including cascaded emitters and superradiance from complex multilevel emitter ensembles. I will further discuss how the native metastability of the emitting electron in realistic systems influences spontaneous emission, highlighting the role of non-Hermitian open-system effects in shaping emission rates and offering a revised perspective on the century-old Fermi’s golden rule.

I will then turn to waveguide-based platforms for generating and manipulating quantum light. By engineering the mode structure and coupling between guided modes, the modal degree of freedom can be used as a synthetic dimension for quantum interactions. I will demonstrate how this enables the implementation of beamsplitters and interferometers entirely within the modal synthetic dimension, enabling the robust generation of key photonic states in a single passive waveguide. These approaches provide scalable, on-chip integrated architectures for photon-state generation and manipulation, highlighting the potential of structured photonic environments to implement complex quantum-optical operations in compact and experimentally feasible platforms.

Ph.D. student Under the supervision of Prof. Meir Orenstein.