Coherent control of quantum topological states of light in Fock-state lattices

TL;DR

This paper demonstrates the realization and control of topological quantum states of light in superconducting circuits, revealing quantum topological phenomena like edge currents and Landau levels, thus bridging condensed matter physics and quantum optics.

Contribution

It introduces a method to create and manipulate topological states of quantized light in a circuit QED setup, extending topological photonics into the quantum regime.

Findings

Observation of topological transport of zero-energy states

Demonstration of strain-induced pseudo-Landau levels

Detection of valley Hall effect and chiral edge currents

Abstract

Topological photonics provides a novel platform to explore topological physics beyond traditional electronic materials and stimulates promising applications in topologically protected light transport and lasers. Classical degrees of freedom such as polarizations and wavevectors are routinely used to synthesize topological light modes. Beyond the classical regime, inherent quantum nature of light gives birth to a wealth of fundamentally distinct topological states, which offer topological protection in quantum information processing. Here we implement such experiments on topological states of quantized light in a superconducting circuit, on which three resonators are tunably coupled to a gmon qubit. We construct one and two-dimensional Fock-state lattices where topological transport of zero-energy states, strain induced pseudo-Landau levels, valley Hall effect and Haldane chiral edge currents are demonstrated. Our study extends the topological states of light to the quantum regime, bridges topological phases of condensed matter physics with circuit quantum electrodynamics, and offers a new freedom in controlling the quantum states of multiple resonators.