Quantum Tunneling of Magnetic Domains

What is it about?

Noise phenomena are ubiquitous in nature and often are regarded as an unfortunate background that confounds desirable signals. However, the distribution and correlations of the noise itself can reveal much of the underlying physics of a material. Here, we find that, in our carefully chosen system, the “Barkhausen noise” present in all magnets is actually dominated by correlated quantum tunneling phenomena, in which millions of billions of spins tunnel together to produce “quantum noise.”

Featured Image

Photo by FlyD on Unsplash

Photo by FlyD on Unsplash

Why is it important?

Avalanches are seen in a wide range of classical systems, including earthquakes, deformation of nanostructures, and the operation of photomultiplier tubes. We demonstrated here that similar behavior can be seen in the quantum regime, where large cascades are driven by quantum tunneling. Understanding how such large-scale quantum effects can be created and controlled is an essential element for developing new devices and applications that depend on quantum coherence, such as qubit processors.