Determination of quantized electromagnetic-field state via electron interferometry

We show that the quantum state of the electromagnetic field can be determined by performing electron interferometry and exploiting the ac analogue of the,Aharonov-Bohm effect. The interferometric phase shift is proportional to the magnetic-flux operator, and measurements of output electron intensity for various interferometer geometries yields the Weyl function, which is the Fourier transform of the Wigner function. In contradistinction to optical methods for state determination, this scheme relies on electron interferometry and could enable probing of intracavity field states. Second-order correlations in this context are also discussed.