Improving the coherence time of a quantum system via a coupling to a short-lived system

Date/Time: Mon., 20th October 2014 15:00-16:00 - (room 2010, National Institute of Informatics)

Speaker: Dr. Yuichiro Matsuzaki (NTT Communication Science Laboratories)

Here, we propose a counter-intuitive use of a hybrid system where the coherence time of a quantum system is actually improved via a coupling with an unstable system. If we couple a two-level system with a single NV center, then a dark state of the NV center naturally forms after the hybridization. We show that this dark state becomes robust against environmental fluctuations due to the coupling even when the coherence time of the two-level system is much shorter than that of the NV center. Our proposal opens a new way to use a quantum hybrid system for the realization of robust quantum information processing.