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 (MC2), Kvantteknologi

Andreas Bengtsson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Jonathan Burnett

National Physical Laboratory (NPL)

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Baladitya Suri

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Indian Institute of Science

Sankar Raman Sathyamoorthy

Chalmers, Mikroteknologi och nanovetenskap (MC2), Tillämpad kvantfysik

Hampus Renberg Nilsson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Marco Scigliuzzo

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Jonas Bylander

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Göran Johansson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Tillämpad kvantfysik

Per Delsing

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

npj Quantum Information

20566387 (eISSN)

Vol. 7 1 140

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Annan elektroteknik och elektronik

DOI

10.1038/s41534-021-00480-5

Mer information

Senast uppdaterat

2021-10-11