A crystal several centimeters long has exhibited quantum behavior. Until now, this type of phenomenon was mainly studied with very small particles.
The researchers observed that several components of the material reacted together: their behavior seemed linked, as if they were part of the same system.
Quantum entanglement presents itself as a link connecting several particles or atoms in a coherent state.
Credit: TU Darmstadt
This phenomenon is called quantum entanglement. It occurs when several particles become so linked that their behavior can no longer be studied separately. The scientists detected coordinated action between several microscopic elements of the material.
The crystal contains cerium, palladium, and silicon. It belongs to a family called "strange metals." These materials conduct electricity in a way that is difficult to explain with classical theories: their electrons seem to act collectively, instead of moving as completely independent particles.
To study this behavior, the researchers sent neutrons at the crystal. They then observed the material's reaction. In a classical solid, each disturbance mainly affects one particle or presents a precise excitation. Here, several elements reacted together, which indicates the presence of a collective quantum link.
This does not mean that all the atoms in the crystal are directly connected to each other. Rather, the experiment shows that a large group of particles shares a common behavior. The result is still interesting, as this phenomenon was measured in an object large enough to be visible and manipulated.
This discovery could help understand why strange metals sometimes conduct current with little fluctuation. Their electrons could act in a coordinated manner, instead of moving separately.
In the longer term, this type of material could be integrated into quantum technologies.