All quantum systems interact with their environments to some extent. Such interactions lead to novel behavior, including driven dissipative phase transitions and non-equilibrium phases that have no analog in closed equilibrium systems. We develop novel techniques to control these interactions and experimentally demonstrate their significant influence on the system properties and dynamics. I will focus here on two experiments. First, a novel non-destructive imaging technique that allows us to control the measurement strength on an ultracold atomic gas, which we use to show how under continuous measurement, the atom dynamics exhibits a quantum to classical transition through the quantum Zeno effect. On the other end of the spectrum, we use a macroscopic Silicon Nitride membrane resonator and demonstrate a novel feedback scheme to control the system-bath interactions. We realize with it a driven dissipative phase transition and show that the phase diagram is modified by the system-bath interactions with emergent phases and novel critical behavior.
Host: Jack Harris