Superconducting pi qubit with a ferromagnetic Josephson junction

TL;DR

This paper introduces a novel superconducting pi qubit utilizing a ferromagnetic Josephson junction, aiming to enhance coherence times and simplify design for scalable quantum computing.

Contribution

It proposes a new qubit design with a ferromagnetic pi junction that operates without external magnetic fields, potentially improving coherence and scalability.

Findings

Qubit operates without external magnetic field

Design potentially reduces decoherence

Simplified structure for integration

Abstract

Solid-state qubits have the potential for the large-scale integration and for the flexibility of layout for quantum computing. However, their short decoherence time due to the coupling to the environment remains an important problem to be overcome. We propose a new superconducting qubit which incorporates a spin-electronic device: the qubit consists of a superconducting ring with a ferromagnetic pi junction which has a metallic contact and a normal Josephson junction with an insulating barrier. Thus, a quantum coherent two-level state is formed without an external magnetic field. This feature and the simple structure of the qubit make it possible to reduce its size leading to a long decoherence time.