Pulse-controlled quantum gate sequences on a strongly coupled qubit chain

TL;DR

This paper introduces a pulse control method for selectively decoupling and implementing high-fidelity quantum gates on strongly coupled qubit chains, especially suited for superconducting flux qubits.

Contribution

It presents a novel dynamical decoupling scheme enabling precise control of coupled qubits using local pulses, facilitating scalable quantum gate operations.

Findings

High-fidelity single- and two-qubit gates achieved

Sequences of gates implementable solely by pulse control

Applicable to strongly coupled superconducting flux qubits

Abstract

We propose a selective dynamical decoupling scheme on a chain of permanently coupled qubits with XX type interactions, which is capable of dynamically suppressing any coupling in the chain by applying sequences of local pulses to the individual qubits. We demonstrate that high-fidelity single- and two-qubit gates can be achieved by this procedure and that sequences of gates can be implemented by this pulse control alone. We discuss the applicability and physical limitations of our model specifically for strongly coupled superconducting flux qubits. Since dynamically modifying the couplings between flux qubits is challenging, they are a natural candidate for our approach.