Simultaneous wide-field imaging of phase and magnitude of AC magnetic signal using diamond quantum magnetometry

Takayuki Iwasaki,Mutsuko Hatano,Kosuke Mizuno,Hitoshi Ishiwata,Yuta Masuyama

doi:10.1038/s41598-020-68404-5

Takayuki Iwasaki, Mutsuko Hatano + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-68404-5

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Abstract

Spectroscopic analysis of AC magnetic signal using diamond quantum magnetometry is a promising technique for inductive imaging. Conventional dynamic decoupling like XY8 provides a high sensitivity of an oscillating magnetic signal with intricate dependence on magnitude and phase, complicating high throughput detection of each parameter. In this study, a simple measurement scheme for independent and simultaneous detection of magnitude and phase is demonstrated by a sequential measurement protocol. Wide-field imaging experiment was performed for an oscillating magnetic field with approximately 100,upmu hbox {m}-squared observation area. Single pixel phase precision was 2.1^{circ } for 0.76,upmu hbox {T} AC magnetic signal. Our method enables potential applications including inductive inspection and impedance imaging.

Highlights

A negatively charged nitrogen-vacancy (NV) center in diamond offers a promising material platform for quantum sensing[1,2]
The wide-field observation area was approximately 100 × 100 μm[2 ], and we estimated that single pixel precision for phase sensing was 2.1◦ with 0.76 μT AC magnetic signal
We propose a new measurement protocol for an oscillating magnetic field based on iQdyne

Summary

Introduction

A negatively charged nitrogen-vacancy (NV) center in diamond offers a promising material platform for quantum sensing[1,2]. Fourier analysis extracts two resulting parameters, magnitude I(bz) and phase θ (φ0) , which are separated from each other and are readily interpretable We implemented this stroboscopic protocol on a wide-field microscope and demonstrated an imaging experiment of an oscillating magnetic field generated from a current pattern fabricated on a diamond substrate. The wide-field observation area was approximately 100 × 100 μm[2 ], and we estimated that single pixel precision for phase sensing was 2.1◦ with 0.76 μT AC magnetic signal This demonstration is a fundamental part of a local current investigation technique. The XY8 sequence is a well-studied quantum sensing scheme, a sort of DD technique, providing excellent sensitivity for oscillating magnetic signals (Fig. 1a). Splicing the Fourier spectrum at the signal frequency and moving to the IQ diagram, the magnitude of the spectrum depends only on the signal magnitude, and the phase of spectrum directly accords with a signal phase (Fig. 1b)

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Discussion

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