Weyl Josephson Circuits

TL;DR

This paper introduces Weyl Josephson circuits, a novel superconducting circuit design that simulates Weyl band structures, enabling the exploration of topological phases and transitions in a controllable, experimental setting.

Contribution

The authors develop a general method to design Josephson circuits simulating Bloch Hamiltonians and demonstrate a six-junction device that realizes a 3D Weyl Hamiltonian with tunable topological phases.

Findings

The six-junction device successfully simulates a Weyl Hamiltonian.

Topological phase transitions can be triggered in situ.

Superconducting circuits can probe topological properties beyond condensed matter limits.

Abstract

We introduce Weyl Josephson circuits: small Josephson junction circuits that simulate Weyl band structures. We first formulate a general approach to design circuits that are analogous to Bloch Hamiltonians of a desired dimensionality and symmetry class. We then construct and analyze a six-junction device that produces a 3D Weyl Hamiltonian with broken inversion symmetry and in which topological phase transitions can be triggered \emph{in situ}. We argue that currently available superconducting circuit technology allows experiments that probe topological properties inaccessible in condensed matter systems.