A Laser-Free and Compact Broadband Magnetometer Based on van der Waals Magnet CrCl3

Abstract

Measuring absolute magnetic fields with high precision is valuable for numerous scientific and technological applications, including physics research, biomedical imaging, navigation systems, and materials characterization. Two-dimensional (2D) vdW materials, with their characteristic weak interlayer (van der Waals) bonding, are well suited for transfer onto a diverse range of substrates, making them amenable to a variety of sensing platforms. In this article, we explored the potential of CrCl₃, a 2D vdW magnetic material, for application in a compact, laser-free absolute magnetometer. We found that the proposed CrCl₃-based magnetometer provides electrical detection of the absolute magnetic field with nanotesla sensitivity, features a simple, compact design, and a small form factor, demonstrating a clear, attractive technology pathway. The sensor material is fabricated using Scotch tape-based room-temperature mechanical exfoliation processes, operates over a wide magnetic field and temperature range, and is robust at ambient conditions. The demonstrated magnetometer's sensitivity is ∼30 nT/√Hz at a 1 T applied magnetic field, and it can track magnetic field changes in real time at a rate exceeding 0.8 mT/s.