Quantum measurement backaction: From single atoms to optomechanical systems

14 12/2015

Monday, 14 Dec. 2015, 17:30 - 18:30

Presenter: Mukund Vengalattore
Host: Peter Rabl
Where: Ernst-Mach-Hörsaal, 2. Stck., Strudlhofgasse 4, Wien

The act of measurement has profound consequences on a quantum system. I will describe our studies on measurement-induced dynamics of an ultracold lattice gas. Using a nondestructive imaging technique that preserves the quantum state of the atoms, we show that the act of imaging these atoms induces their localization - a manifestation of the quantum Zeno effect. Further, by gradually increasing the rate of position measurements, we observe the crossover from a regime of 'weak measurements' - where the act of observation has negligible influence on quantum motion, to the regime of 'strong measurements' - where measurements cause strong localization. This crossover is an instance of emergent classicality in a quantum system when subjected to rapid measurements. I will also discuss our ongoing efforts to extend such measurement-backaction schemes to control macroscopic quantum systems for applications including quantum metrology and the non-equilibrium dynamics of isolated quantum systems.