Emulating topological chiral magnetic effects in artificial Weyl semimetals

TL;DR

This paper demonstrates the emulation of topological chiral magnetic effects in superconducting quantum circuits by mapping lattice momentum space to parameter space, enabling the direct imaging of Weyl points and measurement of topological currents.

Contribution

It introduces a method to realize and measure Weyl semimetal properties and chiral magnetic effects in superconducting circuits, a novel approach for topological quantum simulation.

Findings

Weyl points were directly imaged in superconducting circuits.

Topological currents proportional to magnetic fields were observed.

Berry curvature measurements confirmed topological properties.

Abstract

We realized highly tunable Weyl semimetal-bands and subsequently emulated the topological chiral magnetic effects in superconducting quantum circuits. Driving the superconducting quantum circuits with elaborately designed microwave fields, we mapped the momentum space of a lattice to the parameter space, realizing the Hamiltonian of a Weyl semimetal. By measuring the energy spectrum, we directly imaged the Weyl points of cubic lattices, whose topological winding numbers were further determined from the Berry curvature measurement. In particular, we used an additional microwave field to produce a momentum-dependent chemical potential, from which the chiral magnetic topological current was extracted in the presence of an artificial magnetic field. This pure topological current is proportional to the magnetic field, which is in contrast to the famous Ampere's law, and may have significant impacts on topological materials and quantum devices.