JQI Seminar

Abstract: We add non-linear and state-dependent terms to quantum field theory. We show that the resulting low-energy theory, non-linear quantum mechanics, is causal, preserves probability and permits a consistent description of the process of measurement. We explore the consequences of such terms and show that non-linear quantum effects can be observed in macroscopic systems even in the presence of de-coherence. We find that current experimental bounds on these non-linearities are weak and propose several experimental methods to significantly probe these effects.

Abstract: Tightly packed ordered arrays of atoms exhibit remarkable collective optical properties, as dissipation in the form of photon emission is correlated. In this talk, I will discuss the many-body out-of-equilibrium physics of atomic arrays, and focus on the problem of Dicke superradiance, where a collection of excited atoms synchronizes as they decay, emitting a short and intense pulse of light. Superradiance remains an open problem in extended systems due to the exponential growth of complexity with atom number.

We will discuss recent developments at a new scientific interface between quantum optics, nanoscience and quantum information science. Examples include the use of quantum optical techniques for manipulation of individual atom-like impurities at a nanoscale and for realization of hybrid systems combining atoms and atom-like systems with novel photonic devices.