Experimental implementation of partial symmetrization and anti-symmetrization of two-qubit states
Antonín Černoch, Jan Soubusta, Lucie Bartůšková, Miloslav Dušek, Jaromı́r Fiurášek · New Journal of Physics · 2009
We report on experimental realization of tunable two-qubit state filtering using linear optical elements. The filter enables an arbitrary attenuation of either the symmetric or anti-symmetric part of the input two-qubit state. The device uses the encoding of qubits into polarization states of single photons and its operation is based on combination of single- and two-photon interference, selective attenuation and conditional detection. The filter is very flexible and the degree of symmetrization or anti-symmetrization can be easily set by means of variable attenuators. A full quantum process tomography of implemented operations was carried out and the results confirm very good performance of the filter.