Precision improvement of patch potential measurement in a scanning probe equipped torsion pendulum

Ke Li; Hang Yin; Chi Song; Ming Hu; Shun Wang; Pengshun Luo; Zebing Zhou

doi:10.1063/5.0091226

Precision improvement of patch potential measurement in a scanning probe equipped torsion pendulum

Rev Sci Instrum. 2022 Jun 1;93(6):065110. doi: 10.1063/5.0091226.

Authors

Ke Li¹, Hang Yin¹, Chi Song¹, Ming Hu¹, Shun Wang¹, Pengshun Luo¹, Zebing Zhou¹

Affiliation

¹ MOE Key Laboratory of Fundamental Physical Quantities Measurement, Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.

PMID: 35778033
DOI: 10.1063/5.0091226

Abstract

Patch effect is important for ultra-sensitive experiments involving closely spaced conducting surfaces. A scanning probe equipped torsion pendulum is an experimental apparatus for measuring spatial resolved patch potential on conductive surfaces. An effective approach to improve its measurement precision is by the optimization on the amplitude and frequency of the injected signal in the probe. In this paper, a method based on single- and double-frequency signal injection modes is proposed. The analysis results demonstrate that the potential resolution could achieve the level of 2-4 μV/Hz^1/2. In the same integration time, the surface potential precision in the double-frequency mode is twice better than that in the single-frequency mode. In addition, when achieving the same measurement precision, the double-frequency mode takes less time than the single-frequency mode, which improves the measuring efficiency.