Deterministic chaos can act as a decoherence suppressor

作者:Zhang, Jing*; Liu, Yu-Xi; Zhang, Wei-Min; Wu, Lian-Ao; Wu, Re-Bing; Tarn, Tzyh-Jong
来源:Physical Review B, 2011, 84(21): 214304.
DOI:10.1103/PhysRevB.84.214304

摘要

We propose a strategy to suppress non-Markovian decoherence of a qubit by coupling the qubit to a deterministic chaotic setup with the broad power distribution in particular in the high-frequency domain. Although it is widely believed that chaos induces decoherence, we find, surprisingly, that the unitary dynamics induced by the chaotic setup can be helpful for the decoherence suppression. Compared with the existing decoherence control methods such as the usual dynamical decoupling, we do not need to impose high-frequency controls, because the high-frequency components in our method are generated by the chaotic setup, and the design of complex optimized control pulses used in the modified dynamical decoupling approaches is also not necessary. Using superconducting quantum circuits as an example, we demonstrate how to realize our general method. We find that various noises in a wide frequency domain, including low-frequency 1/f, high-frequency ohmic, subohmic, and superohmic noises, can be efficiently suppressed by coupling the qubit to a Duffing oscillator acting as the chaotic setup. Significantly, the decoherence time of the qubit is prolonged approximately 100 times in magnitude.