Deterministic loading and phase shaping of microwaves onto a single artificial atom

TL;DR

This paper demonstrates highly efficient deterministic loading of microwave photons onto a superconducting artificial atom in a 1D waveguide, advancing quantum network capabilities.

Contribution

It introduces a method for deterministic loading of microwave photons with high efficiency onto a single artificial atom using optimized waveforms.

Findings

Loading efficiency exceeds 94% for coherent states.

Deterministic loading of 98.5% efficiency for Fock states.

Phase manipulation enables coherent control of the loading process.

Abstract

Loading quantum information deterministically onto a quantum node is an important step towards a quantum network. Here, we demonstrate that coherent-state microwave photons, with an optimal temporal waveform, can be efficiently loaded onto a single superconducting artificial atom in a semi-infinite one-dimensional (1D) transmission-line waveguide. Using a weak coherent state (average photon number N<<1 with an exponentially rising waveform, whose time constant matches the decoherence time of the artificial atom, we demonstrate a loading efficiency of above 94% from 1D semi-free space to the artificial atom. We also show that Fock-state microwave photons can be deterministically loaded with an efficiency of 98.5%. We further manipulate the phase of the coherent state exciting the atom, enabling coherent control of the loading process. Our results open up promising applications in realizing quantum networks based on waveguide quantum electrodynamics (QED).