Quantum Error Correction with the Gottesman-Kitaev-Preskill Code

TL;DR

The paper reviews the GKP quantum error correction code, highlighting recent technological advances that make its practical implementation in circuit-QED architecture feasible for scalable, fault-tolerant quantum computing.

Contribution

It provides an overview of the GKP code's implementation in circuit-QED and discusses future challenges and opportunities for scalable quantum error correction.

Findings

Recent hardware developments enable practical GKP code implementation.

GKP code is a promising candidate for fault-tolerant bosonic quantum computing.

Scalability and hardware efficiency are key focus areas for future research.

Abstract

The Gottesman-Kitaev-Preskill (GKP) code was proposed in 2001 by Daniel Gottesman, Alexei Kitaev, and John Preskill as a way to encode a qubit in an oscillator. The GKP codewords are coherent superpositions of periodically displaced squeezed vacuum states. Because of the challenge of merely preparing the codewords, the GKP code was for a long time considered to be impractical. However, the remarkable developments in quantum hardware and control technology in the last two decades has made the GKP code a frontrunner in the race to build practical, fault-tolerant bosonic quantum technology. In this Perspective, we provide an overview of the GKP code with emphasis on its implementation in the circuit-QED architecture and present our outlook on the challenges and opportunities for scaling it up for hardware-efficient, fault-tolerant quantum error correction.