Eur. Phys. J. D (2016) 70: 225
https://doi.org/10.1140/epjd/e2016-70386-y

Regular Article

Reconstruction of electromagnetic field states by a probe qubit

¹ Center for Nonlinear and Complex Systems, Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como, Italy
² Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano, Italy
³ Department of Physics, University of Milan, via Celoria 16, 20133 Milano, Italy

^a e-mail: giuliano.benenti@uninsubria.it

Received: 14 June 2016
Received in final form: 6 September 2016
Published online: 25 October 2016

Abstract

We propose a method to measure the quantum state of a single mode of the electromagnetic field. The method is based on the interaction of the field with a probe qubit. The qubit polarizations along coordinate axes are functions of the interaction time and from their Fourier transform we can in general fully reconstruct pure states of the field and obtain partial information in the case of mixed states. The method is illustrated by several examples, including the superposition of Fock states, coherent states, and exotic states generated by the dynamical Casimir effect.