Journal article
Optical and Spin Properties of NV Center Ensembles in Diamond Nano-Pillars
Publication Details
Authors: | Volkova, K.; Heupel, J.; Trofimov, S.; Betz, F.; Colom, R.; MacQueen, R.; Akhundzada, S.; Reginka, M.; Ehresmann, A.; Reithmaier, J.; Burger, S.; Popov, C.; Naydenov, B. |
Publication year: | 2022 |
Journal: | Nanomaterials |
Pages range : | 1516 |
Volume number: | 12 |
Issue number: | 9 |
ISSN: | 2079-4991 |
eISSN: | 2079-4991 |
DOI-Link der Erstveröffentlichung: |
Abstract
Nitrogen-vacancy (NV) color centers in diamond are excellent quantum sensors possessing high sensitivity and nano-scale spatial resolution. Their integration in photonic structures is often desired, since it leads to an increased photon emission and also allows the realization of solid-state quantum technology architectures. Here, we report the fabrication of diamond nano-pillars with diameters up to 1000 nm by electron beam lithography and inductively coupled plasma reactive ion etching in nitrogen-rich diamonds (type Ib) with [100] and [111] crystal orientations. The NV centers were created by keV-He ion bombardment and subsequent annealing, and we estimate an average number of NVs per pillar to be 4300 $\pm$ 300 and 520 $\pm$ 120 for the [100] and [111] samples, respectively. Lifetime measurements of the NVs' excited state showed two time constants with average values of \textgreekt1 $\approx$ 2 ns and \textgreekt2 $\approx$ 8 ns, which are shorter as compared to a single color center in a bulk crystal (\textgreekt $\approx$ 10 ns). This is probably due to a coupling between the NVs as well as due to interaction with bombardment-induced defects and substitutional nitrogen (P1 centers). Optically detected magnetic resonance measurements revealed a contrast of about 5{\%} and average coherence and relaxation times of T2 [100] = 420 $\pm$ 40 ns, T2 [111] = 560 $\pm$ 50 ns, and T1 [100] = 162 $\pm$ 11 \textgreekms, T1 [111] = 174 $\pm$ 24 \textgreekms. These pillars could find an application for scanning probe magnetic field imaging.
Nitrogen-vacancy (NV) color centers in diamond are excellent quantum sensors possessing high sensitivity and nano-scale spatial resolution. Their integration in photonic structures is often desired, since it leads to an increased photon emission and also allows the realization of solid-state quantum technology architectures. Here, we report the fabrication of diamond nano-pillars with diameters up to 1000 nm by electron beam lithography and inductively coupled plasma reactive ion etching in nitrogen-rich diamonds (type Ib) with [100] and [111] crystal orientations. The NV centers were created by keV-He ion bombardment and subsequent annealing, and we estimate an average number of NVs per pillar to be 4300 $\pm$ 300 and 520 $\pm$ 120 for the [100] and [111] samples, respectively. Lifetime measurements of the NVs' excited state showed two time constants with average values of \textgreekt1 $\approx$ 2 ns and \textgreekt2 $\approx$ 8 ns, which are shorter as compared to a single color center in a bulk crystal (\textgreekt $\approx$ 10 ns). This is probably due to a coupling between the NVs as well as due to interaction with bombardment-induced defects and substitutional nitrogen (P1 centers). Optically detected magnetic resonance measurements revealed a contrast of about 5{\%} and average coherence and relaxation times of T2 [100] = 420 $\pm$ 40 ns, T2 [111] = 560 $\pm$ 50 ns, and T1 [100] = 162 $\pm$ 11 \textgreekms, T1 [111] = 174 $\pm$ 24 \textgreekms. These pillars could find an application for scanning probe magnetic field imaging.
