Under extreme pressure, hydrogen, like many elements, exhibits peculiar behavior that defies conventional understanding. Theoretical predictions suggest that under pressures exceeding a million times that of our atmosphere, hydrogen transforms into a metal and, even more remarkably, a superconductor—a material capable of conducting electricity without resistance.
Scientists have long sought to comprehend and harness the potential of superconducting hydrogen-rich compounds, known as hydrides, for a range of applications, from levitating trains to advanced particle detectors. However, studying the behavior of these materials under immense pressure presents significant challenges, with accurate measurement often verging on the impossible.
In a bid to address this dilemma, researchers from Harvard University have proposed a groundbreaking solution, published in Nature. They have ingeniously integrated quantum sensors into a conventional pressure-inducing device, allowing direct measurement of the electrical and magnetic properties of pressurized materials.
This innovative approach stems from a collaborative effort between Professor of Physics Norman Yao Ph.D., and Boston University professor Christopher Laumann, who transitioned from theoretical backgrounds to tackle the practicalities of high-pressure measurement.
Traditionally, the study of hydrides under extreme pressure involves the use of a diamond anvil cell, which compresses a small amount of material between two diamond interfaces. Detecting the onset of superconductivity typically relies on observing a drop in electrical resistance and the repulsion of nearby magnetic fields—a phenomenon known as the Meissner Effect.
However, accessing detailed information from within the chamber poses a formidable challenge due to the enclosed and high-pressure environment. To overcome this hurdle, the researchers devised a novel retrofit: they integrated quantum sensors, known as nitrogen vacancy centers, directly onto the surface of the diamond anvil. These sensors allow for the imaging of regions inside the chamber as the sample undergoes pressurization and transitions into a superconducting state.
To validate their approach, the researchers focused on cerium hydride, a material known to exhibit superconductivity at extreme pressures.
The introduction of this groundbreaking tool not only facilitates the discovery of new superconducting hydrides but also streamlines the study of existing materials with coveted properties. By optimizing synthesis processes based on real-time observations, researchers can enhance the quality and efficiency of superconducting materials.
The integration of quantum sensors into pressure-inducing devices marks a significant leap forward in the study of high-pressure materials, opening new avenues for exploration and discovery in the field of superconductivity.
Source: Harvard University