Frontiers of quantum cooperative light-matter interfaces

Light is a key player for the sustainability of life on Earth. Through the ages, it continues to fascinate and stimulate humans curiosity towards scientific discoveries using principles of classical and quantum physics, in various fields such as energy production, navigation, and long-distance communication. In quantum optics, the radiation properties of an atom depend on its electromagnetic environment. In a group of atoms sufficiently close together, it depends on interatomic interactions. This behavior is known as the quantum cooperative phenomenon, which is a performance of a team of quantum emitters experiencing the presence of one another. As a result, their collective decay gets suppressed or enhanced, i.e., they exhibit subradiance or superradiance. This project will theoretically estimate and engineer novel collective radiation properties at one side with bio-inspired nano-rings, which possess superior optical properties than other compositions of emitter-array structures and on the other side deals with atomic ensembles. Nature has abundantly engineered complex rings of light-harvesting complexes [LHCs] and relies on them to facilitate the highly efficient photosynthetic process. Here, we will investigate the excitation dynamics of bio-inspired model nanoscale rings, where light excites one dipole, and then the excitation travels through a network of rings. Mimicking the complex bio-LHCs, we will attempt to improve the existing ring designs and extend the current theoretical models to explain more realistic collective light effects. In particular, the goal will be to realize more sustainable, resilient, scalable, and experimentally feasible ring designs for realistic implementations, for example, in semiconductor interfaces to harness solar energy in harsh weather conditions. We will also attempt to establish the influence of site- controlled engineering of an impurity atom on rings, induce long-range interactions in direction to create long-range molecules and engineering single-photon emission with nanoscale rings. With many- body systems, we plan to study the light scattering-induced density modification in a cold atomic gas. We will then investigate scopes for obtaining super-radiant bursts and generation of many-body entanglement. We aim to develop an in-house Julia language code that will be freely available to the scientific community. Altogether, our research goals will open up novel scopes for room-temperature photo-physics and remain resourceful for future applications in many quantum technologies. In long run, the results of this project would hold promise to transform the industry that will eventually shape social policies and contribute to building a better society.