# Chiral Magnetic Josephson junction: a base for low-noise superconducting qubits?

## TL;DR

This paper proposes a novel superconducting qubit design using a Chiral Magnetic Josephson junction, which leverages parity-breaking effects in non-centrosymmetric superconductors to enable low-noise, flux-free quantum computing elements.

## Contribution

It introduces the concept of a Chiral Magnetic Josephson junction as a new qubit element with tunable Hamiltonian, avoiding flux bias and enhancing noise robustness.

## Key findings

- Demonstrates the analog of the Chiral Magnetic Effect in NCS-based Josephson junctions.
- Proposes a qubit architecture that is less sensitive to magnetization fluctuations.
- Shows potential for simplified, robust superconducting qubits.

## Abstract

Superconducting materials with non-centrosymmetric lattices lacking the space inversion symmetry are known to exhibit a variety of interesting parity-breaking phenomena, including the anomalous Josephson effect. Here we consider a Josephson junction consisting of two non-centrosymmetric superconductors (NCSs) connected by a uniaxial ferromagnet, and demonstrate that it exhibits a direct analog of the Chiral Magnetic Effect observed in Dirac and Weyl semimetals. We propose to use this "Chiral Magnetic Josephson junction" (CMJ junction) as an element of a qubit with a Hamiltonian tunable by the ferromagnet's magnetization. The CMJ junction allows to avoid the use of an offset magnetic flux in inductively shunted qubits, thus enabling a simpler and more robust architecture. The resulting"`chiral magnetic qubit" is protected from the noise caused by fluctuations in magnetization when the easy axis of the uniaxial ferromagnet is directed across the junction.