Strange metals have puzzled scientists for decades, defying the conventional laws of electricity and magnetism that govern ordinary conductors like copper and gold. Unlike traditional metals, whose electrical properties can be described using well-established principles, strange metals exhibit behavior that challenges our understanding of quantum physics. Their resistance to electricity does not follow the usual temperature dependence, and their electrons seem to interact in ways that cannot be explained by standard models.
Now, physicists at Rice University have made a major breakthrough in deciphering the mysteries of these enigmatic materials. Using quantum Fisher information (QFI)—a concept borrowed from quantum information science—their research has revealed that electron entanglement reaches its peak at a crucial tipping point known as the quantum critical point. This discovery, published in Nature Communications, provides new insight into the nature of strange metals and could ultimately contribute to advancements in superconducting technology, potentially revolutionizing the way energy is transmitted and used.
Quantum Entanglement and the Role of QFI
To understand the unusual behavior of strange metals, the Rice University research team, led by physicist Qimiao Si, turned to QFI, a tool commonly used in quantum metrology. QFI helps quantify how electron interactions evolve under extreme conditions, offering a new way to measure quantum correlations that were previously difficult to study.
In most metals, electrons behave as distinct particles, following predictable paths. However, in strange metals, these electrons become highly entangled, meaning their quantum states are interconnected regardless of distance. This entanglement plays a key role in the metal’s unconventional properties. The researchers found that as the system approaches a quantum critical point—the boundary between two different states of matter—electron entanglement peaks, leading to the disappearance of quasiparticles.
Quasiparticles are fundamental to describing electrical behavior in metals. They act as “packets” of energy that carry charge through the material. In strange metals, however, quasiparticles vanish at the quantum critical point, leading to the breakdown of conventional theories of electrical resistance. The use of QFI allowed the team to track this breakdown, providing a clearer picture of the deep quantum correlations governing strange metal behavior.
Bridging Quantum Information Science and Condensed Matter Physics
The application of QFI to strange metals marks a significant step forward in materials research. Traditionally, condensed matter physics and quantum information science have been considered separate fields, but this study demonstrates how tools from one discipline can unlock secrets in another. By integrating quantum information theory into the study of exotic materials, scientists are now able to probe quantum correlations with unprecedented precision.
“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.”
This novel approach not only enhances our understanding of strange metals but also provides a new framework for studying other unconventional materials. It opens up possibilities for investigating materials that could be crucial for next-generation quantum technologies, where enhanced entanglement is a valuable resource.
The Connection to High-Temperature Superconductors
The significance of this discovery extends beyond theoretical physics. Strange metals are closely related to high-temperature superconductors, which are materials capable of conducting electricity without energy loss at relatively high temperatures. Unlike traditional superconductors that require extreme cooling near absolute zero, high-temperature superconductors operate at more practical temperatures, making them more feasible for real-world applications.
Scientists have long suspected that quantum entanglement plays a key role in the behavior of these superconductors. By identifying entanglement as a driving force in strange metals, the Rice University study strengthens this connection. If researchers can harness this understanding, it could lead to the development of new superconducting materials that improve energy efficiency on a global scale.
Superconductors have the potential to transform power grids by eliminating energy loss during transmission. Currently, significant amounts of electricity are wasted as heat due to resistance in conventional power lines. The ability to develop room-temperature or high-temperature superconductors would revolutionize energy infrastructure, making electricity transmission far more efficient and sustainable.
Experimental Validation and Future Directions
One of the most exciting aspects of the study is that the theoretical calculations align with real-world experimental data. The researchers’ findings match results from inelastic neutron scattering—a powerful technique used to probe materials at the atomic level. This agreement between theory and experiment reinforces the idea that quantum entanglement is a fundamental driver of strange metal behavior.
The study also highlights the broader implications of using quantum information tools to explore complex materials. As quantum computing and quantum communication technologies continue to evolve, understanding how quantum entanglement functions in different materials could have practical applications beyond superconductivity.
Looking ahead, scientists will continue to investigate how QFI can be applied to other exotic phases of matter. The ability to measure quantum correlations with high precision opens up new possibilities for materials science, quantum computing, and energy research.
A Step Closer to Unlocking Quantum Materials
The discovery made by Rice University physicists represents a significant leap forward in understanding one of the most perplexing classes of materials in modern physics. Strange metals have long been a mystery, resisting explanation through conventional theories. By demonstrating the role of quantum entanglement and introducing QFI as a powerful analytical tool, this study lays the foundation for future breakthroughs in quantum materials research.
Beyond solving a fundamental puzzle, this work has the potential to impact technologies that could shape the future. From next-generation superconductors to advancements in quantum computing, the insights gained from this research may lead to innovations that transform energy efficiency and computation. As scientists continue to probe the quantum world, the strange metals that once defied explanation may become the key to unlocking some of the most promising materials of the future.
Reference: Yuan Fang et al, Amplified multipartite entanglement witnessed in a quantum critical metal, Nature Communications (2025). DOI: 10.1038/s41467-025-57778-7