Kramers-protected hardware-efficient error correction with Andreev spin qubits

TL;DR

This paper introduces a Kramers-protected, hardware-efficient error correction architecture using Andreev spin qubits, enabling projective measurements and logical gates for noise-biased quantum computing.

Contribution

It presents a novel error correction scheme with a feasible architecture for Andreev spin qubits, integrating stabilizer-based protection and measurement techniques.

Findings

Design of a static Hamiltonian with stabilizers of a bit-flip code

Reflectometry enables projective measurement of stabilizers

Circuit-mediated couplings facilitate logical gate operations

Abstract

We propose an architecture for bit-flip error correction of Andreev spins that is protected by Kramers' degeneracy. Specifically, we show that a coupling network of linear inductors and Andreev spin qubits results in a static Hamiltonian composed of the stabilizers of a bit-flip code. The electrodynamics of the many-body spin states also respect these stabilizers, and we show how reflectometry off a single coupled resonator can thereby accomplish their projective measurement. We further show how circuit-mediated spin couplings enable error correction operations and a complete set of single- and two-module logical quantum gates. The concept, which we dub the Ising molecule qubit (or Isene), is experimentally feasible and provides a path for compact noise-biased qubits.