Lattice Surgery with a Twist: Simplifying Clifford Gates of Surface Codes

TL;DR

This paper introduces a surface-code-based quantum computation scheme that reduces overhead for Clifford gates and enables efficient long-range multi-target CNOTs using twist defects, enhancing fault tolerance and universality.

Contribution

It presents a novel lattice surgery protocol with twist defects that simplifies Clifford gates and achieves scalable long-range multi-target CNOTs.

Findings

Eliminates time overhead for single-qubit Clifford gates using classical tracking.

Enables long-range multi-target CNOTs with logarithmic time overhead.

Supports fault-tolerant universal quantum computation via magic state distillation.

Abstract

We present a planar surface-code-based scheme for fault-tolerant quantum computation which eliminates the time overhead of single-qubit Clifford gates, and implements long-range multi-target CNOT gates with a time overhead that scales only logarithmically with the control-target separation. This is done by replacing hardware operations for single-qubit Clifford gates with a classical tracking protocol. Inter-qubit communication is added via a modified lattice surgery protocol that employs twist defects of the surface code. The long-range multi-target CNOT gates facilitate magic state distillation, which renders our scheme fault-tolerant and universal.