Artificial diamond sensor realizes new breakthrough in high temperature superconductor

Abstract Dmitry Budker, a professor of physics at the University of California, USA, and Ben Gurion University in Israel, recently published a groundbreaking study showing that synthetic diamond sensors can detect minute magnetic fields within high-temperature superconductors. This advancement could potentially address long-standing scientific challenges and open new frontiers in materials science. The findings were published in the February issue of *Physical Review*.

While some properties of high-temperature superconductors have been studied since 1987—earning a Nobel Prize for early discoveries—many technological hurdles remain. Diamond sensor technology is now playing a crucial role in overcoming these barriers. According to Budker, who works at the Lawrence Berkeley National Laboratory, this innovation allows scientists to better understand and manipulate superconducting materials.

High-temperature superconductors operate when materials like tantalum or niobium are cooled to about -280°F (180 degrees above absolute zero). In contrast, conventional superconductors require temperatures just a few degrees above absolute zero. Since their discovery nearly 30 years ago, researchers have hoped that room-temperature superconductivity could revolutionize power transmission and transportation. For example, superconducting cables could enable lossless electricity transfer, while maglev trains could reach speeds over 500 km/h. However, achieving these goals requires deeper insights into the behavior of superconducting materials.

“Diamond sensor technology will drive a major leap forward in both the theory and application of high-temperature superconductors,” said Ron and Folman from Ben Gurion University.

Diamonds come in various colors, such as yellow, orange, and purple, due to structural imperfections. These color centers arise when impurities like boron replace carbon atoms in the diamond lattice, altering its optical properties.

With advances in synthetic diamond production, scientists have learned to manipulate these optical characteristics by introducing impurities. In experiments, researchers used nitrogen atoms to displace carbon atoms in synthetic diamonds, creating vacancies. When heated, these vacancies pair with nitrogen atoms, forming nitrogen-vacancy (NV) centers. These centers are highly sensitive to magnetic fields and can be detected using laser spectroscopy, making them ideal for diamond-based sensing.


Folman noted that the quantum properties of these color centers are unique and not found in other materials. Diamond sensors offer exceptional sensitivity and resolution, operating at much higher temperatures than traditional superconducting quantum interferometers. This makes them more adaptable for studying high-temperature superconductors.

Budker emphasized that current magnetometry tools are insufficient for advanced research on superconducting materials. He believes that diamond sensors, with their superior performance, are essential for future breakthroughs.

In their experiments, the team used diamond sensors to examine YBCO (yttrium barium copper oxide), one of the most widely studied high-temperature superconductors. They integrated the diamond sensor with a YBCO sheet on a single chip and observed the transition from normal conduction to superconductivity. The sensors detected tiny eddy currents during this phase change, which appeared and disappeared intermittently. This finding is critical for understanding the underlying mechanisms of high-temperature superconductivity.

Folman added, “Our results show that diamond sensors can effectively monitor high-temperature superconductors. We plan to develop even more sensitive sensors to study individual eddy currents and uncover previously unknown features.”

The research was supported by the NATO Science Peace Program, the National Science Foundation, and the Institute of Basic Sciences at the University of California, Berkeley. (Based on the article "Colored diamonds are a superconductor's best friend")