Diamond’s importance in science extends far beyond its brilliance and luxury appeal. Researchers value the material for its exceptional hardness, remarkable ability to conduct heat, and transparency across much of the light spectrum. About 20 years ago, scientists uncovered another surprising property: under specific conditions, diamond can behave as a superconductor, allowing electrical current to move without resistance.
For years, however, researchers struggled to understand the physics behind this phenomenon, limiting efforts to use superconducting diamond in advanced technologies.
Now, scientists from Pennsylvania State University, the University of Chicago Pritzker School of Molecular Engineering and the U.S. Department of Energy-backed Q-NEXT, led by Argonne National Laboratory, say they have uncovered crucial clues explaining how superconductivity emerges inside diamond.
By engineering ultra-high-quality diamond structures and separating genuine electronic signals from background material noise, the team was able to reveal mechanisms that had remained hidden for decades.
The findings, published in the Proceedings of the National Academy of Sciences, could open the door to multifunction quantum chips capable of combining several quantum technologies within a single platform.
Researchers believe the breakthrough could help bridge one of quantum computing’s biggest challenges — connecting different types of qubits, or quantum bits, that often struggle to work together efficiently. Diamond, they say, may provide a rare material platform capable of supporting multiple quantum functions simultaneously while remaining thermally efficient and compatible with existing electronics.
“This offers a new way of thinking by integrating superconducting and semiconductor behavior to create opportunities for multifunction quantum devices,” said David Awschalom, professor of Quantum Science and Engineering and Physics at UChicago PME and director of the Chicago Quantum Exchange.
Awschalom said future technologies could potentially combine light, spin, superconductivity and magnetism within a single engineered material that also integrates with modern microelectronics.
“There’s enormous potential at the interface between these nominally disparate areas of science,” he said, adding that deeper atomic-scale engineering could unlock entirely new classes of quantum systems.
How it works
In order to become superconducting, diamond must be “doped” with atoms of boron. (Doping is the process of adding different atoms to a host material to control or change certain properties, such as electrical conductivity).
In the study, the scientists used a facility at Penn State’s Applied Research Lab to synthesize extremely high-quality diamond thin films doped with a random distribution of boron. Surprisingly, the research team found hidden order within this disordered distribution of boron in the form of a mosaic of superconducting “puddles” that must eventually link up to allow electricity to flow without resistance – which they describe as “granular superconductivity”. These puddles might form due to clustering of boron atoms within diamond, however even in microscopically uniform films, the superconductivity was found to be granular. More importantly, the superconducting mosaic is seemingly tunable and can be stretched and skewed by changing the magnetic field, electrical current and temperature.
“The graduate student leading the project discovered complex patterns in the electrical behavior of the films that could only be explained by intrinsic granularity,” said Nitin Samarth, Verne M. Willaman Professor of Physics and Materials Science and Engineering at Penn State and co-corresponding author of the paper. “This serendipitous discovery caught us totally by surprise because these are structurally homogeneous, crystalline films! So, the question was: where is this granularity coming from?”
By identifying how electrons move through and between these superconducting puddles, scientists can now begin to “stitch” these superconducting puddles together more effectively, which could significantly boost the performance and temperature range of future quantum devices. Currently, these systems require extreme cooling to function; raising that temperature would make quantum technology more accessible and energy-efficient.
Potential for new innovations
One of the most exciting implications of this research, says Awschalom, is the potential for multifunctional ‘quantum-on-chip’ applications, where multiple different types of quantum information technologies—like quantum communication and quantum computing—could coexist and work together on a single diamond chip. This is due to diamond’s built-in “spin-photon interface,” meaning it naturally connects light to matter without any other technology necessary.
As the quantum industry looks to develop a domestic diamond supply chain, this “all-in-one” diamond platform offers a path toward chips that are not only more powerful but also easier to integrate with the classical high-frequency electronics we use today.
These applications are only possibilities, but the study has taken a critical step: by understanding the underlying principles behind superconductivity in diamond, researchers can now move beyond simply observing it to actively engineering it.
“We now have a reliable roadmap for engineering diamond superconductors by independently adjusting the material’s core properties,” says Samarth, “By tuning parameters like boron doping density, crystalline orientation, mechanical strain, and dimensionality, we can move beyond simple observation and start designing diamond superconductors for specific roles. There are a lot of exciting possibilities here, for both quantum and classical technology.”
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