Coherent output of photons from coupled superconducting transmission line resonators controlled by charge qubits

TL;DR

This paper explores how coupled superconducting resonators with charge qubits can coherently control microwave photons, enabling slow, stopped, or laser-like photon outputs for quantum information processing.

Contribution

It introduces a method to manipulate microwave photons using coupled resonators and charge qubits, creating an on-chip quantum device with tunable photonic properties.

Findings

Coupled resonators form an artificial photonic crystal with engineered band structure.

Charge qubits can modify the band-gap to control photon propagation.

Potential for on-chip laser-like photon generation via population inversion.

Abstract

We study the coherent control of microwave photons propagating in a superconducting waveguide consisting of coupled transmission line resonators, each of which is connected to a tunable charge qubit. While these coupled line resonators form an artificial photonic crystal with an engineered photonic band structure, the charge qubits collectively behave as spin waves in the low excitation limit, which modify the band-gap structure to slow and stop the microwave propagation. The conceptual exploration here suggests an electromagnetically controlled quantum device based on the on-chip circuit QED for the coherent manipulation of photons, such as the dynamic creation of laser-like output from the waveguide by pumping the artificial atoms for population inversion.