Kathrine Frich
Humanity’s understanding of the universe has always evolved with each new discovery.
People once believed the Earth was flat, and later that our planet sat at the center of all creation.
Both ideas eventually gave way to deeper knowledge, reminding us that even our most confident assumptions can be overturned.
A new study from physicists in the United States and Japan suggests that we may be entering another moment of scientific reconsideration, this time at the quantum level.
Unexpected behavior
Researchers at the University of Michigan report that they have observed quantum oscillations inside a material that should, according to long-established theory, be an insulator.
The work, carried out with support from the US National Science Foundation and the Department of Energy, shows that these oscillations arise from the bulk of the material rather than its surface.
Their findings, published in Physical Review Letters, challenge the assumption that only metals or special surface states can exhibit such behavior.
Lu Li, the project’s lead investigator, acknowledged the discovery’s unusual nature. He said the result does not immediately point to a technological breakthrough but does reveal a phenomenon that scientists cannot yet fully explain.
Probing the mystery
Quantum oscillations in metals occur because electrons respond like tiny vibrating springs when exposed to magnetic fields.
For insulators, which are not supposed to conduct electricity or heat, the same effect should be impossible.
Yet in recent years, experiments have repeatedly shown these oscillations in certain exotic insulating compounds, prompting debate about whether the signals come from their outer layers or from deep inside.
To test this, the team used the world’s most powerful magnets at the National High Magnetic Field Laboratory.
Their measurements indicated that the oscillations originate throughout the material. Li said the result leaves researchers with clear evidence but no ready explanation.
Global collaboration
The project involved scientists from multiple institutions in the United States and Japan.
Researcher Kuan-Wen Chen said the group had been working to determine whether the oscillations were intrinsic or related to external effects. Their data confirmed that the signals arise naturally from the material’s bulk.
The compound studied, ytterbium boride (YbB12), was placed under magnetic fields reaching 35 Tesla, far beyond everyday laboratory conditions.
A new kind of duality
Li described the work as part of a “new duality” in physics, where certain materials behave as both insulators and metals depending on their environment.
This idea echoes an earlier scientific shift, when matter was found to be both wave and particle.
Here, the material appears insulating under normal conditions but becomes metal-like when exposed to extreme magnetic forces.
Graduate researcher Yuan Zhu said the next step is to identify the neutral particles responsible for the oscillations. The team hopes the findings will inspire more experimental and theoretical research into this unusual behavior.
Sources: University of Michigan; Physical Review Letters, Science daily.
