Generating, manipulating, and probing local and distant quantum interactions

Quantum interactions between electrons can give rise to emergent phenomena such as magnetism and superconductivity. While such interactions are most commonly manifest locally, photon-mediated interactions between distant atoms can arise via their coupling to a common electromagnetic mode or by quantum interference. Here I will describe how we can engineer, manipulate, and optically probe both local and non-local particle interactions in two distinct material platforms.

First, I will present how we can control the electronic interactions in two dimensions in so-called moiré quantum materials, which are formed by stacking two atomic layers with either a slight twist or lattice mismatch. Here, the electronic interaction between the two layers results in a spatially periodic potential-energy landscape that can create flat bands and quench the kinetic energy of electrons, giving rise to strongly correlated electron systems. I will introduce and discuss the physics of moiré superlattices made by stacking two layers of transition metal dichalcogenide semiconductors together with a slight twist which we can optically probe.

Second, I will present how we can engineer quantum correlations arising due to path erasure from multiple distant but indistinguishable quantum dots. To probe the indistinguishability of the emitters, their dephasing, and the degree of correlation in the joint system that can be coherently controlled we characterize the emergence of “bunching” at zero delay in an intensity correlation experiment. To achieve quantum correlations in a scalable fashion with multiple indistinguishable quantum emitters, we introduce the use of spatial light modulators to independently control the excitation and collection of an arbitrary number of indistinguishable quantum dots. These results establish techniques to rapidly characterize indistinguishability of multiple emitters, to multiplex quantum light sources, to achieve scalable quantum light sources as inputs for programmable quantum circuits, and to engineer and manipulate large Dicke states.

Finally, I will provide a forward-looking perspective in generating and manipulating local and distant quantum interactions, with a particular focus on collaborative interactions within IPAQS in the near future.