September 9, 2025• Physics 18, s109
A minuscule diamond containing billions of impurities can be induced to produce enough force to bend a cantilever.
Over the past two decades, a major research effort has focused on defects called nitrogen-vacancy (NV) centers that can be introduced into diamond. These defects make excellent quantum sensors because their electron spins are highly sensitive to magnetic, electric, and thermal fields. And they have potential applications in quantum information processing, as their spins can be optically polarized at room temperature and have long lifetimes and coherence times. Now Gabriel Hétet and his colleagues at the École Normale Supérieure in France have shown how NV centers can also generate a spin-dependent force that is strong enough to bend a cantilever [1]. This force might offer insights into the interplay between quantum physics and classical physics.
An NV center forms when two adjacent carbon atoms in a diamond’s crystal lattice are replaced with a nitrogen atom and a lattice vacancy. Hétet and his colleagues took a micrometer-scale diamond, doped it with billions of NV centers, and attached it to the end of a micrometer-scale silicon cantilever. They then subjected the diamond to a uniform magnetic field and to green laser light, which polarized the electron spins of the NV centers. The interaction between the polarized spins and the magnetic field produced a force that deflected the cantilever’s end. The force’s strength and direction depended on the orientation of the spins with respect to the field.
The researchers say that this force could help scientists develop hybrid quantum–classical technologies that couple spin systems to mechanical ones, extending the uses of NV centers in quantum sensing.
–Ryan Wilkinson
Ryan Wilkinson is a Corresponding Editor for Physics Magazine based in Durham, UK.
ReferencesM. Perdriat et al., “Spin-dependent force from an NV center ensemble on a microlever,” Phys. Rev. B 112, 094419 (2025).Subject AreasRelated Articles
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