2023 Fiscal Year Annual Research Report
Enhanced quantum sensing with a nitrogen-vacancy centre as gateway to the electron spin of phosphorus
| Project/Area Number |
22K14560
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| Research Institution | Kyoto University |
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Principal Investigator |
ヘルブスレブ デイヴィト 京都大学, 化学研究所, 特定助教 (40817904)
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| Project Period (FY) |
2022-04-01 – 2024-03-31
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| Keywords | Quantum sensing / Standard deviation / Robust sensing / Dark matter / Doping |
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| Outline of Annual Research Achievements |
This report is written with respect to the three main points in the last report (phosphorus concentration, NV centre couples, new measurement method), and it is given below.
1) We increased the phosphorus concentration to about 10^17 atoms/cm^3. This still did not show any response at the expected energy transition. We measured in the order of 100 NV centres (via specially written automation software), but no valleys indicating a resonance showed up.
2) We were able to solve the problem with the stability of the charge state of the NV centre. Now, most (~80%) of the measured couples of NV centres retain their charge state, making them stable to measure for a long time. However, the coherence time (T2) was only slightly better: each pair of NV centres had a coherence time of about 3 us. This is not enough for measuring the coupling between them, which is expected to be in the order of kHz.
3) We designed a new measurement method which we call the "standard deviation quantum sensing" method. We have analysed it analytically, with numerical simulations and with measurements on a single NV centre. The results are written up in a manuscript which is currently under review. This opens up a new class of detectors to use in particle physics. Followup research will try to create the lowest limit on light dark matter using the electron-axion coupling using this technique and an ensemble of NV centres for increasing the sensitivity.
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