Somewhere in the quantum realm, a small carnival is going on. Researchers have created ultra-small suspended diamonds, with a diameter equivalent to 350 strands of human DNA, that spin more than a billion times a minute and reflect light like a disco ball.
These tiny party decorations are the invention of Purdue University scientists, who are using them to make ultra-precise measurements that could help illuminate the relationship between quantum mechanics and gravity. There have been attempts to levitate nanodiamonds before, but actually making it work requires extremely precise conditions.
“In the past, experiments with these floating diamonds have had difficulty preventing them from being lost in the vacuum and reading out the spin qubits,” Tongcang Li, a professor of physics and astronomy at Purdue University, said in a statement. “However, in ours In our work, we successfully suspended diamonds in high vacuum using a special ion trap. For the first time, we were able to observe and control the behavior of spin qubits inside suspended diamonds in high vacuum.
Qubits are the quantum version of computer bits, the basic unit of quantum information, in which semiconductor materials are used to capture the charge of a single electron and its associated spin. To create the necessary conditions to study how the diamond’s rotation affects spin qubits, the researchers had to spin the diamond at a dizzying speed of 1.2 billion revolutions per minute.
They achieved this by using photolithography, the same technique used to make computer chips, to create a sapphire wafer coated with 300 nanometers of gold. The diamonds themselves, with an average diameter of 750 nanometers, are formed under high pressure and temperature, accelerating natural processes that create the sparkling rock. Diamonds contain tiny structures that can host electron spin qubits.
To measure a diamond’s rotation, a green laser shines on the diamond, causing it to glow red. This light, in turn, allows researchers to determine the electron’s spin state. Another type of laser is used to monitor the rotation of the nanodiamonds. As the nanodiamond spins, it scatters the laser’s infrared light like a disco ball.
A paper in the journal describes the new technology nature communications, The researchers say it will allow the study of exciting concepts such as quantum physics, but also have practical applications, such as using it for precise accelerometers and electric field sensors.
Unfortunately, there’s no word on whether the team will also be able to invent tiny glow sticks.
