Preparation and manipulation of a fault-tolerant superconducting qubit

TL;DR

This paper presents a method to encode, prepare, and manipulate a fault-tolerant superconducting qubit using continuous variables in an rf SQUID, enabling quantum computation with error correction.

Contribution

It introduces a novel encoding scheme in continuous variables for superconducting qubits, demonstrating fault-tolerant state preparation and manipulation techniques.

Findings

Fault-tolerant state can be prepared in an rf SQUID

Operations enable quantum computation and error correction

Discussion of error sources and system imperfections

Abstract

We describe a qubit encoded in continuous quantum variables of an rf superconducting quantum interference device. Since the number of accessible states in the system is infinite, we may protect its two-dimensional subspace from small errors introduced by the interaction with the environment and during manipulations. We show how to prepare the fault-tolerant state and manipulate the system. The discussed operations suffice to perform quantum computation on the encoded state, syndrome extraction, and quantum error correction. We also comment on the physical sources of errors and possible imperfections while manipulating the system.