Toward Highly Efficient Multimode Superconducting Quantum Memory
Aleksei R. Matanin, K. I. Gerasimov, E. S. Moiseev, Nikita S. Smirnov, Аnton I. Ivanov, Elizaveta I. Malevannaya, Victor I. Polozov, E. V. Zikiy, Andrey A. Samoilov, Ilya A. Rodionov, С. А. Моисеев
Abstract
We experimentally demonstrate a microwave quantum storage for two spectral modes of microwave radiation in an on-chip system of eight coplanar superconducting resonators. Single-mode storage shows a power efficiency of up to $60\ifmmode\pm\else\textpm\fi{}3\mathrm{%}$ at single photon energy and more than $73\ifmmode\pm\else\textpm\fi{}3\mathrm{%}$ at higher intensity. The noiseless character of the storage is confirmed by coherent-state quantum process tomography. The demonstrated efficiency is an order of magnitude higher than the previously reported data for multimode microwave quantum memory. The proposed on-chip quantum memory architecture can be easily integrated into the state-of-the-art superconducting quantum circuit technology without any coherence compromises. The obtained results are in good agreement with the proposed theory, which pave the way for building a practical multimode microwave memory for superconducting quantum circuits.