Limits on preserving quantum coherence using multipulse control

作者:Khodjasteh Kaveh*; Erdelyi Tamas; Viola Lorenza
来源:Physical Review A, 2011, 83(2): 020305.
DOI:10.1103/PhysRevA.83.020305

摘要

We explore the physical limits of pulsed dynamical decoupling methods for decoherence control as determined by finite timing resources. By focusing on a decohering qubit controlled by arbitrary sequences of p pulses, we establish a nonperturbative quantitative upper bound to the achievable coherence for specified maximum pulsing rate and noise spectral bandwidth. We introduce numerically optimized control "bandwidth-adapted" sequences that saturate the performance bound and show how they outperform existing sequences in a realistic excitonic-qubit system where timing constraints are significant. As a by-product, our analysis reinforces the impossibility of fault-tolerance accuracy thresholds for generic open quantum systems under purely reversible error control.

  • 出版日期2011-2-28