Building logical qubits in a superconducting quantum computing system

TL;DR

This paper discusses the development of logical qubits using superconducting qubits and surface codes, highlighting recent technological progress and future engineering challenges towards scalable fault-tolerant quantum computers.

Contribution

It introduces a route for creating logical qubits with superconducting qubits using a rotated surface code, advancing quantum memory development.

Findings

Progress in superconducting qubit networks

Implementation of a rotated surface code

Identification of near-term technological improvements

Abstract

The technological world is in the midst of a quantum computing and quantum information revolution. Since Richard Feynman's famous "plenty of room at the bottom" lecture, hinting at the notion of novel devices employing quantum mechanics, the quantum information community has taken gigantic strides in understanding the potential applications of a quantum computer and laid the foundational requirements for building one. We believe that the next significant step will be to demonstrate a quantum memory, in which a system of interacting qubits stores an encoded logical qubit state longer than the incorporated parts. Here, we describe the important route towards a logical memory with superconducting qubits, employing a rotated version of the surface code. The current status of technology with regards to interconnected superconducting-qubit networks will be described and near-term areas of focus to improve devices will be identified. Overall, the progress in this exciting field has been astounding, but we are at an important turning point where it will be critical to incorporate engineering solutions with quantum architectural considerations, laying the foundation towards scalable fault-tolerant quantum computers in the near future.