Dynamical Suppression of Decoherence and Protection of Quantum Coherence Between Superconducting Flux Qubits in 1/f Noise Environments by Bang-Bang Pulses.

We investigate how to protect the quantum coherence and quantum Fisher information for two superconducting flux qubits each locally interacting with its own finite-temperature environment (heat bath) with 1/f spectral density by making use of bang-bang pulses. It is shown that the quantum coherence and quantum Fisher information can be improved by applying a train of bang-bang pulses and protected more effectively with shorter interval pulses. In addition, we also explore the influence of bang-bang pulses on the transfer of quantum information between two flux qubits and heat baths by a witness of trace distance. It is found that the bang-bang pulses can suppress the effect of heat baths and slow down the exchange of the quantum information flows between two flux qubits and heat baths. [ABSTRACT FROM AUTHOR]