How to count one photon and get a(n average) result of 1000… (in binary)
I will present our recent experimental work using electromagnetically induced transparency in laser-cooled atoms to measure the nonlinear phase shift created by a single post-selected photon, and its enhancement through "weak-value amplification." Put simply, due to the striking effects of "post-selective" quantum measurements, a (very uncertain) measurement of photon number can yield an average value much larger than one, even when it is carried out on a single photon. I will say a few words about possible practical applications of this "weak value amplification" scheme, and their limitations.
Time permitting, I will also describe other future and past work related to quantum metrology and ultracold atoms – in particular, we have implemented a quantum-information-inspired protocol to beat “Rayleigh’s curse” for resolving closely-separated spots in classical imaging; and we have preliminary evidence of a narrow Fabry-Perot resonance for atoms.
Hosted by Mohammad Hafezi and Charles Clark.