Scientists Develop Quantum Sensor Scheme to Detect Antiferromagnets

Physicists from the University at Buffalo have introduced a theoretical scheme for a quantum sensor designed to detect antiferromagnets, a new class of magnetic materials. This was reported by Quantum Insider.

The study is published in Physical Review Letters. It does not introduce a new type of magnetism but rather a method to detect antiferromagnetic order. Currently, the system exists only on paper and requires experimental validation.

The concept involves using a diamond with a nitrogen-vacancy (NV) defect: a nitrogen atom adjacent to a vacancy in the lattice. This defect is sensitive to local magnetic fields. It is placed near the suspected antiferromagnet, the spin is oriented in various directions, and the relaxation rate is measured. If the relaxation is found to be anisotropic, it may indicate a complex magnetic order, a hallmark of antiferromagnets.

The authors emphasize a less invasive approach. Existing methods often exert too much influence on the sample, making it difficult to separate the material's intrinsic properties from measurement effects.

The corresponding author is Jamir Marino, an assistant professor of physics at the University at Buffalo. Co-authors include Libor Šmejkal and Jairo Sinova from Johannes Gutenberg University in Mainz, who are recognized at their university as the researchers who first proposed the concept of antiferromagnets. The study also involved Hossein Hosseinabadi and V.A.S.V. Bittencourt.

Interest in antiferromagnets is growing due to their potential applications in electronics. These materials combine zero net magnetization, like antiferromagnets, with the electronic effects of ferromagnets. The potential lies in faster and more energy-efficient information transfer.

Signs of antiferromagnetism have already been observed in several materials. Theoretical calculations suggest more than 200 potential compounds, increasing the demand for precise identification methods.

A key outcome of this work is not a ready-made sensor but a measurement protocol. This could serve as a foundation for future experiments aimed at discovering and confirming antiferromagnetic order.

In May, Quantinuum and energy giant BP launched a joint project to apply quantum computing for subsurface probing and mapping of the Earth's resources.