Bang-Bang control of a qubit coupled to a quantum critical spin bath

Rossini, Davide; Facchi, Paolo; Fazio, Rosario; Florio, Giuseppe; Lidar, Daniel A.; Pascazio, Saverio; Plastina, Francesco; Zanardi, Paolo

Bang-Bang control of a qubit coupled to a quantum critical spin bath

Authors

Description

We analytically and numerically study the effects of pulsed control on the decoherence of a qubit coupled to a quantum spin bath. When the environment is critical, decoherence is faster and we show that the control is relatively more effective. Two coupling models are investigated, namely a qubit coupled to a bath via a single link and a spin star model, yielding results that are similar and consistent.
10 pages, 4 figures, replaced with published version