Universal Quantum Computation Using Continuous Dynamical Decoupling

TL;DR

This paper demonstrates that continuous dynamical decoupling can protect two-qubit coherence during quantum operations, enabling robust universal quantum computation with exchange interactions and simple control fields.

Contribution

It introduces a method combining continuous dynamical decoupling with exchange interactions to achieve robust, universal quantum computation against environmental noise.

Findings

Coherence of two-qubit states preserved during SWAP operations.

Continuous dynamical decoupling enhances robustness against environmental perturbations.

Control fields are simple and suitable for experimental implementation.

Abstract

We show, for the first time, that continuous dynamical decoupling can preserve the coherence of a two-qubit state as it evolves during a SWAP quantum operation. Hence, because the Heisenberg exchange interaction alone can be used for achieving universal quantum computation, its combination with continuous dynamical decoupling can also make the computation robust against general environmental perturbations. Furthermore, since the exchange-interaction Hamiltonian is invariant under rotations, the same control-field arrangement used to protect a stationary quantum-memory state can also preserve the coherence of the driven qubits. The simplicity of the required control fields greatly improves prospects for an experimental realization.