Hardware-Efficient Fault Tolerant Quantum Computing with Bosonic Grid States in Superconducting Circuits

TL;DR

This paper discusses how bosonic grid states in superconducting circuits can enable scalable, hardware-efficient fault-tolerant quantum computing by leveraging multiple bosonic modes for enhanced error correction.

Contribution

It introduces a multi-mode bosonic encoding approach that improves error correction and fault tolerance in superconducting quantum processors, extending beyond traditional GKP codes.

Findings

Bosonic modes enable hardware-efficient error correction.

Multi-mode encoding enhances protection against control errors.

Recent demonstrations support the feasibility of this architecture.

Abstract

Quantum computing holds the promise of solving classically intractable problems. Enabling this requires scalable and hardware-efficient quantum processors with vanishing error rates. This perspective manuscript describes how bosonic codes, particularly grid state encodings, offer a pathway to scalable fault-tolerant quantum computing in superconducting circuits. By leveraging the large Hilbert space of bosonic modes, quantum error correction can operate at the single physical unit level, therefore reducing drastically the hardware requirements to bring fault-tolerant quantum computing to scale. Going beyond the well-known Gottesman-Kitaev-Preskill (GKP) code, we discuss how using multiple bosonic modes to encode a single qubit offers increased protection against control errors and enhances its overall error-correcting capabilities. Given recent successful demonstrations of critical components of this architecture, we argue that it offers the shortest path to achieving fault tolerance in gate-based quantum computing processors with a MHz logical clock rate.