Analysis of nanodiamond based single-photon sources on plasmonic platform
Yen-Chun Chen1*, Chi-Fu Hsu1, Chun-Yuan Wang2, Wei-Chen Chien3, Watson Kuo3, Shangir Gwo2, Wen-Hao Chang1
1Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Physics, National Tsing Hua University, Hsinchu, Taiwan
3Physics, National Chung Hsing University, Taichung, Taiwan
* presenting author:陳衍均,
We demonstrate a large-area plasmonic platform with self-aligned local hot spots for enhancing single photon emissions from nanodiamonds (NDs). Our approach is based on a metal-oxide-diamond hybrid structure consisting of NDs on top of a platform formed by 5-nm-Al2O3-layer capped single crystalline gold flakes [1]. The strongly confined plasmonic fields in the thin dielectric layer can lead to a large enhancement (×6) in the ND fluorescence intensity without significant degradation in single photon purity. We further analyze the dependence of the plasmonic enhancement on the dipole orientation of nitrogen-vacancy (NV) centers (the direction connecting N and V) by optically detected magnetic resonance (ODMR) [2]. By changing the magnetic field direction and measuring the ground-state Zeeman splitting, the dipole orientation of NV center can be identified. We found that the plasmonic enhancement reaches a maximum when the NV dipole is parallel to the metal surface. The plasmonic platform combined with single NV centers is highly promising for quantum information applications.

Keywords: single-photon source, nitrogen-vacancy center, plasmonic enhancement, Zeeman effect, optically detected magnetic resonance