BGU Physics Department

Colloquium, Nov. 3rd, 2011

Weak Values and Precision Measurements

John Howell, Department of Physics and Astronomy, University of Rochester

Weak values were originally introduced by Aharanov, Albert and Vaidman for understanding the arrow of time in quantum mechanics. Weak values have recently proved useful in amplifying very small effects. I will introduce the ideas of weak values and discuss some of our recent experimental results in which we were able to observe a deflection of a laser beam of less than 1 picoradian (equivalent to measuring a deflection of the width of a hair at the distance of the moon). Perhaps more interestingly, the noise properties lead to a suppression of technical noise and an amplification of the signal to noise ratio to the optimal value for coherent states for standard beam deflection techniques. I will also discuss the use of weak values and precision deflection measurements for precision spectral and phase measurements.