1.
Phys Rev Lett
; 104(10): 103602, 2010 Mar 12.
Artículo
en Inglés
| MEDLINE
| ID: mdl-20366424
RESUMEN
We study the sensitivity and resolution of phase measurement in a Mach-Zehnder interferometer with two-mode squeezed vacuum (n photons on average). We show that superresolution and sub-Heisenberg sensitivity is obtained with parity detection. In particular, in our setup, dependence of the signal on the phase evolves n times faster than in traditional schemes, and uncertainty in the phase estimation is better than 1/n, and we saturate the quantum Cramer-Rao bound.