Quantum wave mixing and visualisation of coherent and superposed photonic states in a waveguide

A Yu Dmitriev,T Hönigl-Decrinis,V N Antonov,O V Astafiev,R Shaikhaidarov

doi:10.1038/s41467-017-01471-x

Abstract

Superconducting quantum systems (artificial atoms) have been recently successfully used to demonstrate on-chip effects of quantum optics with single atoms in the microwave range. In particular, a well-known effect of four wave mixing could reveal a series of features beyond classical physics, when a non-linear medium is scaled down to a single quantum scatterer. Here we demonstrate the phenomenon of quantum wave mixing (QWM) on a single superconducting artificial atom. In the QWM, the spectrum of elastically scattered radiation is a direct map of the interacting superposed and coherent photonic states. Moreover, the artificial atom visualises photon-state statistics, distinguishing coherent, one- and two-photon superposed states with the finite (quantised) number of peaks in the quantum regime. Our results may give a new insight into nonlinear quantum effects in microwave optics with artificial atoms.

Highlights

Superconducting quantum systems have been recently successfully used to demonstrate on-chip effects of quantum optics with single atoms in the microwave range
In systems with superconducting quantum circuits—artificial atoms—strongly coupled to harmonic oscillators, many amazing phenomena of on-chip quantum optics have been recently demonstrated establishing the direction of circuit quantum electrodynamics[1,2,3], in such systems one is able to resolve photon number states in harmonic oscillators[4], manipulate with individual photons[5,6,7], generate photon (Fock) states[8] and arbitrary quantum states of light[9], demonstrate the lasing effect from a single artificial atom[10], study nonlinear effects[11, 12]
We demonstrate the physical phenomenon of quantum wave mixing (QWM) on a superconducting artificial atom in the open one-dimensional (1D) space

Summary

Introduction

Superconducting quantum systems (artificial atoms) have been recently successfully used to demonstrate on-chip effects of quantum optics with single atoms in the microwave range. Ultimate scaling down of the nonlinear medium to a single artificial atom, strongly interacting with the incident waves, results in time resolution of instant multi-photon interactions and reveals effects beyond classical physics.

Results

Conclusion