Quantum speed-up of multiqubit open system via dynamical decoupling pulses

TL;DR

This paper demonstrates that dynamical decoupling pulses can accelerate the evolution of multiqubit open systems in both weak and strong coupling regimes by controlling non-Markovianity and excited-state populations.

Contribution

It introduces a method to achieve quantum speed-up in multiqubit open systems using dynamical decoupling pulses, explaining the underlying physical mechanism.

Findings

Speed-up achieved in weak and strong coupling regimes

Non-Markovianity and excited-state populations can be controlled by DDPs

Physical mechanism involves reservoir non-Markovianity and qubit excitation

Abstract

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