Ferrimagnetic Oscillator Magnetometer

The detection of magnetic fields is essential for many areas of research and industry, including geophysics, space exploration, and biomedical applications. However, achieving high-sensitivity measurements has often been burdensome because of the need for lasers and precision engineering. Traditional magnetometry, for example, relies on lasers to stimulate fluorescence emission from defect centers in solid-state hosts, a process that can be complex and resource-intensive. There's a growing need for simplified yet equally effective alternatives. Current approaches largely rely on fluorescence emission from nitrogen vacancies in diamonds. While effective, a major limitation is that the stringent requirements placed on the digitizer can complicate the process and make it less ideal for certain applications. A method that could encode magnetic signals in frequency, rather than amplitude, would circumvent this problem and be a pivotal advancement in this field.

Technology Description

Ferrimagnetic oscillator magnetometers are an advanced technology that doesn't involve the use of lasers to stimulate fluorescence emission from defect centers in solid-state hosts. Instead, these devices exploit the natural properties of ferrimagnetic crystals. By applying a magnetic field, the device shifts the resonance of entangled electronic spins housed within the crystal. The spin ensemble has a resonance linewidth that ranges between approximately 370 kHz and 10 MHz. The shifting resonance produces microwave sidebands, the amplitude of which is proportional to the magnetic field strength and frequency proportional to the magnetic field oscillation frequency. These sidebands can be coherently averaged, digitized, and processed, enabling magnetic field measurements with outstanding sensitivity and potentially reaching the spin projection limit of 1 attotesla/√{square root over (Hz)}. This method encodes magnetic signals in frequency rather than amplitude to reduce the typically strict requirements on the digitizer, thereby offering a distinct advantage over existing technologies.