Document Type
Article
Publication Date
12-4-2012
Abstract
We refute the widely held belief that the quantum weak value necessarily pertains to weak measurements. To accomplish this, we use the transverse position of a beam as the detector for the conditioned von Neumann measurement of a system observable. For any coupling strength, any initial states, and any choice of conditioning, the averages of the detector position and momentum are completely described by the real parts of three generalized weak values in the joint Hilbert space. Higher-order detector moments also have similar weak value expansions. Using the Wigner distribution of the initial detector state, we find compact expressions for these weak values within the reduced system Hilbert space. As an application of the approach, we show that for any Hermite-Gauss mode of a paraxial beamlike detector these expressions reduce to the real and imaginary parts of a single system weak value plus an additional weak-value-like contribution that only affects the momentum shift.
Recommended Citation
Dressel, J., Jordan, A.N., 2012. Weak Values are Universal in Von Neumann Measurements. Physical Review Letters 109, 230402. doi:10.1103/PhysRevLett.109.230402
Peer Reviewed
1
Copyright
American Physical Society
Comments
This article was originally published in Physical Review Letters, volume 109, in 2012. DOI: 10.1103/PhysRevLett.109.230402