Scientists can make a graphite plate levitate; Understanding | Sciences

Harry Potter fans are well aware of the “wingardium Leviosa” spell that allows objects to levitate. Researchers at the Okinawa Institute of Science and Technology (OIST) in Japan have achieved something akin to the magic of J. K. Rowling's epic: they have developed a piece of graphite that floats in a vacuum.

The results were published on March 18 in the journal Applied Physics Letters, But they were only released recently, on April 8. The research was conducted by scientists studying levitated matter in the Quantum Machinery Unit at OIST.

The team levitated a thin sheet of graphite onto a platform without relying on external power sources, which may help in developing ultra-sensitive sensors for accurate and efficient measurements.

The researchers chemically coated a powder of graphite microspheres with silica. By mixing the coated powder with wax, they formed a centimeter-thin square plate that floated atop a platform of magnets arranged in a grid pattern.

This type of frictionless platform could have many applications, such as in new types of quantum sensors for measuring force, acceleration and gravity. Since it oscillates without losing energy, this means that once it starts moving, it will continue to oscillate for a long period of time, even without additional energy input.

Reducing the power level is important to make the platform more sensitive when used as a sensor. Moreover, the so-called “quenching” of their movement towards the quantum regime could open up new possibilities for precise measurements.

Why graffiti?

The crystalline form of carbon found in pencils, graphite, strongly repel magnets, which are highly susceptible to magnetism. Being a magnetic material means it can float on strong magnetic fields.

In the experiment, the researchers constantly monitored movement on the platform. Using this information, in real time, they used a magnetic reaction force to dampen its motion, cool it and slow it down.

“Heat causes movement, but by constantly monitoring and providing real-time feedback in the form of corrective actions to the system, we can slow this movement,” explains Jason Twamley, Head of the Quantum Machines Unit at OIST, in a statement. “Feedback adjusts the damping rate of the system, which is how quickly it loses energy, so by actively controlling damping, we reduce the kinetic energy of the system, effectively cooling it.”

According to the expert, if the lifting platform is cooled sufficiently, it could outperform even the most sensitive atomic gravimeters developed to date, which are modern instruments that use the behavior of atoms to precisely measure gravity.

“Achieving this level of accuracy requires rigorous engineering to isolate the platform from external disturbances such as vibrations, magnetic fields and electrical noise,” says Twamley. “Our ongoing work is focused on improving these systems to unleash the full potential of this technology.”