Levitating diamonds spinning at 1.2 billion RPM could unlock quantum gravity secrets

It sounds like something ripped from the pages of science fiction: tiny diamonds floating in a vacuum, spinning at more than a billion revolutions per minute, revealing clues about the fundamental nature of the universe. But that’s exactly what researchers at Purdue University have accomplished—and the implications stretch from quantum physics to the very fabric of gravity itself.

Diamonds in flight: A high-speed quantum experiment

In a meticulously controlled vacuum chamber, scientists have managed to levitate nanodiamonds—each barely 750 nanometers wide—and spin them at a dizzying 1.2 billion RPM. These aren’t ordinary diamonds. They’re engineered to contain nitrogen-vacancy (NV) centers, which behave like ultra-sensitive quantum compasses. These NV centers allow the team to study how electron spins—a quantum property—respond to motion and magnetic fields.

Using a sophisticated setup involving electric fields, laser beams, and custom microwave traps, the team not only kept the diamonds suspended in midair but also read their spin states with extraordinary precision. It’s the first time such measurements have been performed on levitated diamonds in high vacuum, and it’s opening up entirely new frontiers in quantum experimentation.

How spinning diamonds reveal deeper physics

So why spin diamonds that fast? Because in quantum mechanics, motion changes everything. By bombarding the levitated diamonds with green and infrared lasers, researchers can observe how light reflects and scatters from their surfaces—like a microscopic disco ball spinning at hyper speed.

This rotation amplifies a phenomenon known as the Berry phase, a strange twist in quantum physics where particles behave differently depending on how they move. The experiment shows that rotation alters the spin of quantum bits (qubits) inside the diamonds, offering a rare chance to observe how motion, spin, and light interact at the smallest scales.

Why this breakthrough matters beyond the lab

The success of this setup does more than impress physicists—it could transform technology. Levitated systems like this provide ultra-clean environments with minimal interference, making them perfect for building next-generation gyroscopes, field sensors, and quantum communication tools.

Past efforts to spin diamonds in vacuum often failed due to overheating or unstable spin signals. But Purdue’s team overcame those challenges by optimizing the trap design and carefully managing laser heat, keeping the diamond’s internal temperature at a stable 350 K. This means scientists can now control spin states in low-pressure environments, an essential step toward exploring the overlap between quantum mechanics and Einstein’s theory of gravity.

A new platform to explore quantum gravity

One of physics’ biggest mysteries is how to reconcile general relativity with quantum theory. These diamonds could help. By embedding qubits in spinning particles, scientists may one day measure how gravity influences quantum systems, even creating superpositions—where an object exists in multiple states at once.

And it’s not just theory. The U.S. Air Force is already exploring levitated particles for navigation and secure communication, and the potential civilian applications—from precision sensors to quantum encryption—are just beginning to take shape.

Hand-built hardware meets high-level physics

Behind the science is some seriously creative engineering. The trap holding the diamonds is built from a sapphire wafer coated with gold, with additional electrodes for controlling both position and spin. Software simulations helped the team tweak every detail, ensuring stable levitation and efficient microwave transmission.

PhD student Kunhong Shen likened the spinning motion to a chaotic ball of yarn—until voltage inputs smooth it out into precise control. It’s a beautiful mix of art and science, brought to life by a team of students, postdocs, and collaborators working at the cutting edge of levitated optomechanics.

The next step in unraveling the universe

This experiment is more than a technical achievement—it’s a glimpse into a future where we can test the boundaries of physics in entirely new ways. As we continue to explore the strange relationship between quantum spin and gravity, spinning nanodiamonds might just be the key to some of the most profound discoveries of our time.

The research, published in Nature Communications, is a bold reminder that even the tiniest particles, when given the right conditions, can help answer the biggest questions in science.

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