Quantum efficiency, purity and stability of a tunable, narrowband microwave single-photon source
Journal article, 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.

Author

Yong Lu

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Andreas Bengtsson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Jonathan Burnett

National Physical Laboratory (NPL)

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Baladitya Suri

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Indian Institute of Science

Sankar Raman Sathyamoorthy

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Hampus Renberg Nilsson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Marco Scigliuzzo

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Jonas Bylander

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Göran Johansson

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Per Delsing

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

npj Quantum Information

20566387 (eISSN)

Vol. 7 1 140

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1038/s41534-021-00480-5

More information

Latest update

10/11/2021