Scientists have long sought to unravel the mysteries of strange metals—materials that defy conventional rules of electricity and magnetism. Now, a team of physicists at Rice University has made a breakthrough in this area using a tool from quantum information science. Their study, published recently in Nature Communications, reveals that electrons in strange metals become more entangled at a crucial tipping point, shedding new light on the behavior of these enigmatic materials. The discovery could pave the way for advances in superconductors with the potential to transform energy use in the future.

Unlike conventional metals such as copper or gold that have well-understood electrical properties, strange metals behave in much more complex ways, making their inner workings beyond the realm of textbook description. Led by Qimiao Si, the Harry C. and Olga K. Wiess Professor of Physics and Astronomy, the research team turned to quantum Fisher information (QFI), a concept from quantum metrology used to measure how electron interactions evolve under extreme conditions, to find answers. Their research shows that electron entanglement, a fundamental quantum phenomenon, peaks at a quantum critical point: the transition between two states of matter.

“Our findings reveal that strange metals exhibit a unique entanglement pattern, which offers a new lens to understand their exotic behavior,” Si said. “By leveraging quantum information theory, we are uncovering deep quantum correlations that were previously inaccessible.”

For decades, researchers have explored how electrons behave in quantum materials. Under certain conditions, electrons interact strongly with each other instead of moving independently, leading to exotic quantum states. One such state, first proposed by Nobel laureate Eugene Wigner, is the Wigner crystal—a structured electron arrangement caused by their mutual repulsion. Although widely theorized, experimental proof has been rare.

Researchers at Yonsei University have now provided evidence of Wigner crystallization and the associated electronic rotons. In a study published in the journal Nature, Prof. Keun Su Kim and his team used angle-resolved photoemission spectroscopy (ARPES) to analyze black phosphorus doped with alkali metals. Their data revealed aperiodic energy variations, a hallmark of electronic rotons.

Crucially, as they decreased the dopant density within the material, the roton energy gap shrank to zero. This observation confirmed a transition from a fluid-like quantum state to a structured electron lattice, characteristic of Wigner crystallization.

A new solid-state laser produces 193-nm light for precision chipmaking and even creates vortex beams with orbital angular momentum – a first that could transform quantum tech and manufacturing.

Deep ultraviolet (DUV) lasers, which emit high-energy light at very short wavelengths, play a vital role in areas like semiconductor manufacturing, high-resolution spectroscopy, precision material processing, and quantum technology. Compared to traditional excimer or gas discharge lasers, DUV lasers offer better coherence and lower power consumption, making it possible to build smaller, more efficient systems.

Breakthrough in Solid-State Laser Development.

Quantifying the power potential of matter-antimatter reactions in everyday volumes