Decoherence-induced leakage errors can couple a physical or encoded ?qubit to other levels, thus potentially damaging the qubit. They can ?therefore be very detrimental in quantum information processing and ?require special attention. Here we present a method for removing such ?errors by using simple decoupling and recoupling pulse sequences using ?universal leakage elimination operator.? We future extend the ?universal leakage elimination operator to protect arbitrary ?time-dependent bases.

报告人简介：Prof. Lianwo Wu received his PhD in 1989 from the Jilin ?University. He worked in centres in Canada, China, Japan, Europe, and ?the United States. His honors include the Alexander von Humboldt ?fellow, COE (Center of Excellence) professorship, Japanese Ministry of ?education. Now, he is the Ikerbasque Research Professor at the ?Department of Theoretical Physics at the Faculty of Science and ?Technology at the UPV-EHU in Leioa. Research lines include quantum ?control, quantum computation and quantum information, and quantum devices.?