Scientists Develop “Unbreakable” Quantum Sensor Built to Survive 30,000 Atmospheres

Schematic image of a 2D sensor squeezed between two diamond anvils. Credit: Chong Zu, modified by SciTechDaily.com Boron nitride sensors enable quantum measurements under crushing pressure, redefining high-pressure physics. The quantum world is already full of mysteries, but what happens when this strange domain of subatomic particles is subjected to immense pressure? Studying quantum behavior in such conditions has long been a challenge for one simple reason: it is extremely difficult to design sensors that can endure such intense forces. In a major step forward, a team of physicists at Washington University in St. Louis (WashU) has developed quantum sensors made from an ultra-strong sheet of crystallized boron nitride. These sensors are capable of detecting stress and magnetic fields in materials exposed to pressures more than 30,000 times greater than Earth’s atmosphere. “We’re the first ones to develop this sort of high-pressure sensor,” said Chong Zu, assistant professor of physics in Arts & Sciences and a member of WashU’s Center for Quantum Leaps. “It could have a wide range of applications in fields ranging from quantum technology, material science, to astronomy and geology.” The team reported their results in Nature Communications. The paper’s co-authors include graduate students from Zu’s lab—Guanghui He, Ruotian “Reginald” Gong, Zhongyuan Liu, and Changyu Yao; graduate student Zack Rehfuss; postdoctoral researcher Mingfeng Chen; and Xi Wang and Sheng Ran, both assistant professors of physics. How the new quantum sensors were made To construct the sensors, the researchers used neutron radiation beams to remove boron atoms from thin sheets of boron nitride. These atomic vacancies instantly capture electrons, whose spin energies respond sensitively to local changes in magnetic fields, stress, temperature, and other physical conditions. By monitoring the spin behavior of these electrons, scientists can extract detailed, quantum-level information about the materials under investigation. Zu and colleagues previously had created quantum sensors by making vacancies in diamonds, which power WashU’s two quantum diamond microscopes. While effective, diamond sensors have a drawback: Because diamonds are three-dimensional, it’s hard to place the sensors close to the material being studied. In contrast, sheets of boron nitride can be less than 100 nanometers thick — about 1,000 times thinner than a human hair. “Because the sensors are in a material that’s essentially two-dimensional, there’s less than a nanometer (a billionth of a meter) between the sensor and the material that it’s measuring,” Zu said. Diamonds still play an important role. “To measure materials under high pressure, we need to put the material on a platform that won’t break,” He explained. Diamonds, the hardest substance in nature, serve this purpose. He and other members of the Zu lab created “diamond anvils” — two flat diamond surfaces, each about 400 micrometers wide, roughly the width of four dust particles — that squeeze together in a high-pressure chamber. “The easiest way to create high pressure is to apply great force over a small surface,” He explained. Testing materials and future applications Tests showed that the new sensors could detect subtle shifts in the magnetic field of a two-dimensional magnet. Next, the researchers plan to test other materials, including specimens of rocks like those found in the high-pressure environment of the Earth’s core. “Measuring how these rocks respond to pressure could help us better understand earthquakes and other large-scale events,” Zu said. The sensors also could advance research on superconductivity, the ability to conduct electricity without resistance. Currently, known superconductors require extremely high pressure and low temperatures. Previous claims that some materials can act as superconductors at room temperature have proven to be highly controversial. “With this sort of sensor, we can collect the necessary data to end the debate,” said Gong, who, along with He, was co-first author of the paper. The new sensors underscore the value of the NSF NRT training grant, Zu said. “The program encourages collaboration between universities,” he said. “Now that we have these sensors, the high-pressure chamber and the diamond anvils, we’ll have more opportunities for exploration.” Reference: “Probing stress and magnetism at high pressures with two-dimensional quantum sensors” by Guanghui He, Ruotian Gong, Zhipan Wang, Zhongyuan Liu, Jeonghoon Hong, Tongxie Zhang, Ariana L. Riofrio, Zackary Rehfuss, Mingfeng Chen, Changyu Yao, Thomas Poirier, Bingtian Ye, Xi Wang, Sheng Ran, James H. Edgar, Shixiong Zhang, Norman Y. Yao and Chong Zu, 32 August 2025, Nature Communications. DOI: 10.1038/s41467-025-63535-7 The research received support from a National Science Foundation Research Traineeship (NRT) grant, which also enabled He to conduct six months of collaborative work at Harvard University with physicist Norman Yao, who contributed as a co-author.