Quantum efficiency, purity and stability of a tunable, narrowband microwave single-photon source
Artikel i vetenskaplig tidskrift, 2021
We demonstrate an on-demand source of microwave single photons with 71–99% intrinsic quantum efficiency. The source is narrowband (300 kHz) and tuneable over a 600 MHz range around 5.2 GHz. Such a device is an important element in numerous quantum technologies and applications. The device consists of a superconducting transmon qubit coupled to the open end of a transmission line. A π-pulse excites the qubit, which subsequently rapidly emits a single photon into the transmission line. A cancellation pulse then suppresses the reflected π-pulse by 33.5 dB, resulting in 0.005 photons leaking into the photon emission channel. We verify strong antibunching of the emitted photon field and determine its Wigner function. Non-radiative decay and 1/f flux noise both affect the quantum efficiency. We also study the device stability over time and identify uncorrelated discrete jumps of the pure dephasing rate at different qubit frequencies on a time scale of hours, which we attribute to independent two-level system defects in the device dielectrics, dispersively coupled to the qubit. Our single-photon source with only one input port is more compact and scalable compared to standard implementations.
Författare
Yong Lu
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Andreas Bengtsson
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Jonathan Burnett
National Physical Laboratory (NPL)
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Baladitya Suri
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Indian Institute of Science
Sankar Raman Sathyamoorthy
Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik
Hampus Renberg Nilsson
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Marco Scigliuzzo
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Jonas Bylander
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
Göran Johansson
Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik
Per Delsing
Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi
npj Quantum Information
20566387 (eISSN)
Vol. 7 1 140Ämneskategorier
Atom- och molekylfysik och optik
Annan fysik
Annan elektroteknik och elektronik
DOI
10.1038/s41534-021-00480-5