Realization of four-level qudits using biphotons.
The novel experimental realization of four-level optical quantum systems (ququarts) is presented. We exploit the polarization properties of the frequency nondegenerate biphoton field to obtain such systems. A simple method that does not rely on am interferometer is used to generate and measure the sequence of states that can be used in quantum key distribution protocol.
Moreva
E V
EV
Moscow Engineering Physics Institute, State University, Russia. ekaterina.moreva@gmail.com
Maslennikov
G A
GA
Straupe
S S
SS
Kulik
S P
SP