Mere months after their discovery of a room-temperature superconductor, UNLV physicist Ashkan Salamat and colleagues from UNLV and the University of Rochester have recorded a new phenomenon that inches the research closer to reality and could one day “find a place in physics textbooks.”

The phenomenon involves a material — a compound made of manganese and sulfide, compressed in a diamond anvil cell — transitioning from an insulator to a metal, and then back to an insulator, a phenomenon very rarely observed in nature, researchers say.

“The fact that you can manipulate matter in such an aggressive way using very small modulations — in this case pressure — is very insightful about nature’s willingness to be perturbed very aggressively,” said Salamat, associate professor of physics at UNLV. “This is a new type of charge transfer mechanism, and so from a science community point of view this is very, very exciting.”

The recent discovery landed Salamat and colleagues an “editors’ choice” accolade in the journal Physical Review Letters, their second paper in almost as many months to receive the distinction.

It’s the latest step in th

eir quest to achieve room-temperature superconductivity — the “holy grail” of energy efficiency — on a practical scale. First published in October 2020 as a cover story in the journal Nature, Salamat and Ranga Dias, an assistant professor at Rochester, observed room-temperature superconductivity in a diamond anvil cell — a small, handheld, and commonly used research device that enables the compression of tiny materials to extreme pressures — pressures that you’d only find at the center of the Earth.

According to researchers, room-temperature superconductivity could one day change the way we power everything from handheld technology to the grid itself by allowing current to flow through a closed loop forever. It would also result in zero energy lost, an issue that plagues modern tech. The latest discovery moves this promising line of research forward by showing how metals at room temperature can move from one state to another with a relatively small change in pressure. 

“The journey is, now that we can prove these quantum states exist at habitable temperatures, can we find alternative pathways to release the mechanical pressure? With the current trajectory we’re on, it’s looking increasingly promising,” Salamat said.

The paper’s lead author, Dylan Durkee, is a former undergraduate researcher in the Salamat lab at UNLV, with additional contributions from UNLV researchers Keith Lawler, Alexander Smith, and Christian Childs. Other co-authors include Nathan Dasenbrock-Gammon and Elliot Snider at the University of Rochester; Dean Smith at Argonne National Laboratory; and Simon A.J. Kinder at University of Bourgogne.

Publication Details

“Colossal Density-Driven Resistance Response in the Negative Charge Transfer Insulator MnS2” appeared in the July 2, 2021 issue of Physical Review Letters.

The National Science Foundation and the Department of Energy supported the research with funding. The UNLV National Supercomputing Institute provided computational resources, and portions of the work were performed at Argonne National Laboratory and University of Bourgogne.