2003 Volume 72 Issue 2 Pages 181-185
The development of key devices and systems in quantum information technology, such as quantum gates and quantum cryptographic systems, requires a reliable and well-established method for evaluating how well the devices or systems work. We report our recent work on the experimental evaluation of photonic quantum channels, using the methods of process tomography. Evaluation of typical single-qubit decoherence channels has been demonstrated using process tomography. Evaluation of two-qubit channels, such as classically correlated channels and quantum mechanically correlated channels， awaits future studies. The evaluation techniques for quantum channels will be useful for developing photonic quantum devices and for improving their performances.
