Classical Field Approach to Quantum Weak Measurements

Authors

Justin Dressel, Chapman UniversityFollow
Konstantin Y. Bliokh, Interdisciplinary Theoretical Science Research Group, RIKEN,
Franco Nori, Center for Emergent Matter Science, RIKEN

Document Type

Article

Publication Date

3-20-2014

Abstract

By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.

Comments

This article was originally published in Physical Review Letters, volume 112, in 2014. DOI: 10.1103/PhysRevLett.112.110407

Recommended Citation

Dressel, J., Bliokh, K.Y., Nori, F., 2014. Classical Field Approach to Quantum Weak Measurements. Physical Review Letters 112, 110407. doi:10.1103/PhysRevLett.112.110407

Peer Reviewed

1

Copyright

American Physical Society