Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber
Abstract
Long-distance quantum communication requires entanglement between distant quantum memories. For this purpose, photon transmission is necessary to connect the distant memories. Here, for the first time, we develop a two-step frequency conversion process (from a visible wavelength to a telecommunication wavelength and back) involving the use of independent two-frequency conversion media where the target quantum memories are nitrogen-vacancy centers in diamonds (with an emission/absorption wavelength of 637.2 nm), and experimentally characterize the performance of this process acting on light from an attenuated CW laser. A total conversion efficiency of approximately 7% is achieved. The noise generated in the frequency conversion processes is measured, and the signal-to-noise ratio is estimated for a single photon signal emitted by a nitrogen-vacancy (NV) center. The developed frequency conversion system has future applications via transmission through a long optical fiber channel at a telecommunication wavelength for a quantum repeater network.
- Publication:
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Japanese Journal of Applied Physics
- Pub Date:
- June 2018
- DOI:
- 10.7567/JJAP.57.062801
- arXiv:
- arXiv:1805.00174
- Bibcode:
- 2018JaJAP..57f2801T
- Keywords:
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- Quantum Physics
- E-Print:
- 21 pages, 7 figures, submitted to JJAP