Experimental Characterization of Nonideal Two-qubit Quantum Devices by Quantum Process Tomography
Yoshihiro Nambu, Kazuo Torii Nakamura · arXiv (Cornell University) · 2004
Characterization of nonideal two-qubit devices will be important in developing quantum gates. In this letter, nonideal Bell-state filters subject to various degree of decoherence were investigated by quantum process tomography. We found that the experimental results are explained by a simple model and that a common belief that a beamsplitter acts as a singlet-state filter when only the coincidence signal is post-selected is erroneous. In the ideal case it is a triplet-state filter.