Using an optical method to measure magnetostriction at milli-kelvin temperatures

What is it about?

This paper presents an optical method for precisely measuring magnetostrictive strain in cryogenic environments, employing a Fabry–Pérot interferometer setup. The technique accurately determined magnetostrictive strain in neodymium gallate at a temperature of 49 mK, yielding a strain value of λ = 1.3 × 10−5 at 3 T with a sensitivity of 3.0 × 10−8. While showcasing the remarkable sensitivity and calibration-free nature of optical measurement techniques, the study also highlights the crystal's magnetic ordering properties.

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Photo by Finnian Smith on Unsplash

Photo by Finnian Smith on Unsplash

Why is it important?

Magnetostriction is defined as a material's ability to experience mechanical strain when a magnetic field is applied to it. The magnetostriction of a system quantifies the relationship between a system's magnetic and mechanical properties. Rare earth crystal systems exhibit significant magnetisation when subjected to a magnetic field under cryogenic conditions. These rare earth systems show promise in the field of upconversion and quantum memory systems. By exploring the magnetostriction of these materials, we can unlock new insights into the coupling between the magnetisation and mechanical modes of these systems.