New quantum sensors can withstand extreme pressure

The world of quantum physics is already mysterious, but what happens when this strange kingdom of subatomic particles is put under immense pressure? Observation of quantum pressure effects has proven to be difficult for a simple reason: the design of sensors that can withstand extreme forces is difficult.

In an important advance, a team led by physicists from Washu created quantum sensors in an unbreakable leaf of crystallized boron nitride. The sensors can measure stress and magnetism in pressure materials which exceed 30,000 times the pressure from the atmosphere.

“We are the first to develop this type of high pressure sensor,” said Chong Zu, assistant professor of physics in arts and sciences and member of the University of Washington in St. Louis’ Center for Quantum Saups. “It could have a wide range of applications in fields ranging from quantum technology, from materials to astronomy and geology.”

The team described its conclusions in the newspaper Nature communications. The newspaper co-authors are graduate students from the ZU laboratory, notably Guangui He, Rootian “Reginald” Gong, Zhongyuan Liu and Changyu Yao; The graduate student Zack Rehfuss; Postdoctoral researcher Mingfeng Chen; And Xi Wang and Sheng ran, both assistant physics teachers. Guanghui he also spent six months at Harvard University working with the physicist Norman Yao, another co-author.

To create the sensors, the team used neutron radiation beams to eliminate the boron atoms from the slim boron nitride sheets. Vacant posts can immediately trap electrons. Due to quantum interactions, electrons modify their rotation energies as a function of magnetism, stress, temperature and other qualities of materials nearby. Monitoring the rotation of each electron offers deep information at the quantum level on any material studied.

Zu and his colleagues had previously created quantum sensors by making vacant posts in diamonds, which feed the two quantum diamond microscopes of Washu. Although effective, diamond sensors have a drawback: because diamonds are three -dimensional, it is difficult to place the sensors near the material studied.

On the other hand, boron nitride leaves can be less than 100 nanometers thick – about 1,000 times thinner than human hair. “Because the sensors are in an essentially two -dimensional material, there is less than a nanometer (a billionth of a meter) between the sensor and the material it measures,” said Zu.

Diamonds are still playing an important role. “To measure high pressure materials, we have to put the material on a platform that will not break,” he said.

Diamonds, the hardest substance of nature, are used for this objective. He and other members of the ZU laboratory have created “diamondvilies” – two flat diamond surfaces, each about 400 micrometers wide, roughly the width of four dust particles – which tighten together in a high pressure chamber. “The easiest way to create high pressure is to apply great strength to a small surface,” he said.

The tests have shown that new sensors could detect subtle changes in the magnetic field of a two -dimensional magnet. Then, the researchers plan to test other materials, including specimens of rocks such as those found in the high pressure environment of the heart of the earth. “Measuring how these rocks react to pressure could help us better understand earthquakes and other large -scale events,” said Zu.

The sensors could also advance research on superconductivity, the ability to conduct electricity without resistance. Currently, known superconductors require extremely high pressure and low temperatures. The previous affirmations according to which certain materials can act as superconductors at room temperature has been very controversial. “With this type of sensor, we can collect the data necessary to put an end to the debate,” said Gong, who, with him, was co-prime author of the newspaper.

“Now that we have these sensors, the high pressure chamber and the diamond ancals, we will have more exploration opportunities,” said Zu.