John Howell
Universitiy of Rochester
“Wonderful World of Weak Values”
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 are simply remarkable in leading to a suppression of
technical noise and a tremendous amplification of the signal to noise
ratio for standard beam deflection techniques. We have also shown
that a phase amplification in the interferometer can lead to
measurement of the phase at the standard quantum limit while only
observing the dark port of an interferometer.