Scalable quantum computation via local control of only two qubits

TL;DR

This paper demonstrates that universal quantum computation on large spin chains can be achieved by controlling only two qubits at one end, using efficient control sequences suitable for physical systems like superconducting qubits.

Contribution

It introduces a method for scalable quantum computation by local control of just two qubits, enabling universal operations on large chains efficiently.

Findings

Control sequences can be computed efficiently.

Universal quantum gates can be implemented with minimal control.

Applicable to physical systems like superconducting qubits.

Abstract

We apply quantum control techniques to control a large spin chain by only acting on two qubits at one of its ends, thereby implementing universal quantum computation by a combination of quantum gates on the latter and swap operations across the chain. It is shown that the control sequences can be computed and implemented efficiently. We discuss the application of these ideas to physical systems such as superconducting qubits in which full control of long chains is challenging.