@article{oai:repo.qst.go.jp:00049397, author = {Brandenburg, Felix and Nagumo, Ryosuke and Saichi, Kota and Tahara, Kosuke and Iwasaki, Takayuki and Hatano, Mutsuko and Jelezko, Fedor and Igarashi , Ryuji and Yatsui, Takashi and Igarashi, Ryuji}, issue = {1}, journal = {Scientific Reports}, month = {Oct}, note = {The nitrogen-vacancy (NV) centre in diamond is a promising candidate for quantum computing applications and magnetic sensing applications, because it is an atomic-scale defect with stable coherence time (T2) and reliable accessibility at room temperature. We demonstrated a method for improving the NV spin properties (the full width half maximum (FWHM) value of the magnetic resonance spectrum and T2) through a near-field (NF) etching method under ambient conditions. The near-field etching method, based on a He-Cd ultraviolet laser (325 nm), which is longer than the absorption edge of the oxygen molecule, enabled selective removal of defects on the nanodiamond surface. We observed a decrease in the FWHM value close to 15% and an increase in T2 close to 25%. Since our technique can be easily reproduced, a wide range of NV centre applications could be improved, especially magnetic sensing applications. Our results are especially attractive, because they have been obtained under ambient conditions and only require a light source with wavelength slightly above the O2 absorption edge.}, title = {Improving the electron spin properties of nitrogen-vacancy centres in nanodiamonds by near-field etching}, volume = {8}, year = {2018} }