The act of measurement has profound consequences on a quantum system. As such, the evolution of a quantum system can be influenced and even controlled through the continuous measurement of its properties. I will describe our studies on such measurement-induced dynamics in systems ranging from nanoKelvin atomic gases to millimeter-scale mechanical systems. In the former case, we show that the act of imaging ultracold atoms can influence their quantum motion - a manifestation of the Quantum Zeno effect. By gradually increasing the rate of position measurements, we observe the crossover from the regime of 'weak measurements' where measurement has negligible influence on quantum motion, to the regime of 'strong measurements' where the act of measurement causes strong spatial localization. This crossover is an instance of emergent classicality in a quantum system when subjected to rapid measurements. I will discuss our ongoing efforts to extend such measurement-backaction schemes to control mesoscopic optomechanical systems for applications including quantum metrology and the study of non-equilibrium dynamics of isolated quantum systems.

Prof. Vengalattore research interests lie in the experimental study of ultracold atomic gases. Cooled down to a mere fraction of a degree above absolute zero (less than 100 nanoKelvin), these gases display beautiful and often bizarre properties which can be ascribed to the dominant role of quantum mechanics and particle statistics.

Joint CMP-AMO-Purdue Quantum Center Seminar, Department of Physics, Purdue Quantum Center

Researchers should cite this work as follows:

• Mukund Vengalattore (2016), "Quantum Measurement Backaction: From Atoms to Optomechanics," https://nanohub.org/resources/24152.

  BibTex | EndNote

1. cold/ultracold atoms
2. nanophotonics
3. quantum systems