Quantum limits of measurability of the electromagnetic field

With L. Rosenfeld

L.D. Faddeev, L.A. Khalfin, I.V. Komarov

If we assume that the most precise measurements of electromagnetic fields using electrons or protons as “test bodies” have been carried out, then by reason of the quantum mechanical uncertainty principle for the coordinate and momentum of the bodies, we get certain bounds on the measurability of the field intensities, namely, the same bounds for measurements both with electrons and protons. In the sense of the quantum mechanical concepts, it means that these fundamental restrictions on the measurability of the electromagnetic fields suggest a reasonable limitation on the possibility to determine precisely the state of the classical field.

Gerhard Heber

G. Compagno, Franco Persico

We argue that the criticism by Hnizdo [preceding Comment, Phys. Rev. A 60, 4212 (1999)] of the results obtained by Compagno and Persico [Phys. Rev. A 57, 1595 (1998)] on the theory of measurement of the amplitude of the quantum electromagnetic field is unfounded. By a simple and direct approach we show that the quantities evaluated by Hnizdo in his Comment are incorrect and we present the correct results.

H. Pierre Noyes

E. Corinaldesi