Imaging Photon Lattice States by Scanning Defect Microscopy

TL;DR

This paper introduces Scanning Defect Microscopy, a new technique for mapping the normal modes of microwave photons in a lattice of coupled resonators, enabling detailed spatial imaging of photon states in quantum simulators.

Contribution

The work presents a novel measurement method that locally perturbs resonator frequencies to reconstruct photon field distributions in a complex lattice.

Findings

Successfully mapped the normal modes of a 49-site Kagome lattice.

Demonstrated spatial imaging of photon-lattice normal modes.

Provided a new tool for analyzing open-system quantum simulators.

Abstract

Microwave photons inside lattices of coupled resonators and superconducting qubits can exhibit surprising matter-like behavior. Realizing such open-system quantum simulators presents an experimental challenge and requires new tools and measurement techniques. Here, we introduce Scanning Defect Microscopy as one such tool and illustrate its use in mapping the normal-mode structure of microwave photons inside a 49-site Kagome lattice of coplanar waveguide resonators. Scanning is accomplished by moving a probe equipped with a sapphire tip across the lattice. This locally perturbs resonator frequencies and induces shifts of the lattice resonance frequencies which we determine by measuring the transmission spectrum. From the magnitude of mode shifts we can reconstruct photon field amplitudes at each lattice site and thus create spatial images of the photon-lattice normal modes.