Entanglement-enhanced quantum error-correcting codes

Date: 2009-04-30
Authors Ying Dong (董莹), Xiuhao Deng (邓修豪), Mingming Jiang (姜明明), Qing Chen (陈清), and Sixia Yu (郁司夏)
Journal No. Phys. Rev. A 79, 042342 (2009)
Abstract Via explicit examples we show that the pre-existing entanglement can really enhance (not only behave as an assistance for) the efficiency of the quantum error-correcting codes (QECCs) in a single block of encoding or decoding as well as help in beating the quantum Hamming bound. A systematic approach to constructing entanglement-assisted (or enhanced) quantum error-correcting codes (EAQECCs) via graph states is also presented, and an infinite family of entanglement-enhanced codes has been constructed. Furthermore we generalize the EAQECCs to the case of not-so-perfectly protected qubit and introduce the quantity infidelity as a figure of merit and show that the EAQECCs also outperform the ordinary QECCs.