title: Coherence times of precise depth controlled NV centers in diamond.
abstract: We investigated the depth dependence of coherence times of nitrogen-vacancy (NV) centers through precise depth control using oxidative etching at 580 °C in air. By successive nanoscale etching, NV centers could be brought close to the diamond surface step by step, which enabled us to track the evolution of the number of NV centers remaining in the chip and to study the depth dependence of coherence times of NV centers with diamond etching. Our results showed that the coherence times of NV centers declined rapidly with the depth reduction in the last about 22 nm before they finally disappeared, which revealed a critical depth for the influence of a rapid fluctuating surface spin bath. Moreover, by using the slow etching method combined with low-energy nitrogen implantation, NV centers with depths shallower than the initially implanted depths can be generated, which are preferred for detecting external spins with higher sensitivity.
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Lab of Quantum Information, CAS, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Jie
authors.initials: J
authors.lastname: You
authors.affiliation: Key Lab of Quantum Information, CAS, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Lab of Quantum Information, CAS, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Guo
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Fupan
authors.initials: F
authors.lastname: Feng
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Xuerui
authors.initials: X
authors.lastname: Song
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Liren
authors.initials: L
authors.lastname: Lou
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. gzwang@ustc.edu.cn.
authors.forename: Guanzhong
authors.initials: G
authors.lastname: Wang