Quantum speedup of uncoupled multiqubit open system via dynamical decoupling pulses

• DOI: 10.1007/s11128-016-1291-2
• Publication Date: 2016-03-18T14:27:01Z
• Authors: Ya-Ju Song; Le-Man Kuang; Qing-Shou Tan
• Keywords: Speedup; Decoupling (probability); Dynamical decoupling

We present a method to accelerate the dynamical evolution of mutltiqubit open system by employing dynamical decoupling pulses (DDPs) when the qubits are initially in W-type states. Here the qubits are independent and coupled to local Lorentzian reservoirs. It is found that this speedup evolution can be achieved in both the weak-coupling regime and the strong-coupling regime. The essential physical mechanism behind the acceleration evolution is explained as a result of the joint action of the non-Markovianity of reservoirs and the excited-state population of qubits. It is shown that both the non-Markovianity and the excited-state population can be controlled by DDPs to realize the quantum speedup.