Physicists harness quantum entanglement to decode strange metals

Quantum physics is a novel and quite fascinating field of science that continues to intrigue with its existing and potential implementations, including the one where scientists are using quantum entanglement to unravel the mysteries of certain strange metals.

Indeed, materials that defy the rules of electricity and magnetism have long captivated physicists’ imagination across the board as they sought to decode their secrets, but recently one team has made a breakthrough using a tool from quantum information science, per a report by ScienceDaily on March 28.

As it happens, a team of scientists at Rice University, Texas, has found that electrons in these strange materials become more entangled at a critical tipping point, potentially paving the way for advances in superconductors with the potential to transform energy use in the future.

In their work, the research team led by Qimiao Si, the Harry C. and Olga K. Wiess Professor of Physics and Astronomy, has deployed quantum Fisher information (QFI) – a concept from quantum metrology – to measure how electron interactions evolve under extreme conditions.

What the team discovered through quantum entanglement

During the process, the team learned that electron entanglement (a fundamental quantum phenomenon) peaks at a quantum crucial point – the transition between two states of matter. According to Si, this has allowed his team to get new insights into quantum physics:

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

Electrons in most metals follow well-established laws of physics, but a small group bends these rules, shows unusual resistance to electricity, and behaves oddly at very low temperatures – some of the characteristics that the researchers sought to explore by focusing on a theoretical model called the Kondo Lattice.

Specifically, these interactions become so intense at a critical transition point, that the fundamental building blocks of electrical behavior, called quasiparticles, disappear. Through the utilization of QFI, these scientists have traced the origin of this quasiparticle loss to how electron spins become entangled, discovering that entanglement hits its peak at exactly this quantum critical point.

As Si explained, this novel approach relying on QFI, which is by and large used in quantum information and precision measurements, can now apply in the study of metals, commenting that “by integrating quantum information science with condensed matter physics, we are pivoting in a new direction in materials research.”

The results were quite surprising – their theoretical calculations matched real-world experimental data, particularly the results from inelastic neutron scattering (a method for probing materials at the atomic level). As such, this connection has bolstered the idea that quantum entanglement is fundamental to strange metals’ behavior.

Quantum superconductivity implications

Meanwhile, these materials share a close connection with high-temperature superconductors, which might be able to transmit electricity without energy loss, thus possibly making energy transmission more efficient and revolutionizing power grids everywhere.

Speaking of quantum superconductivity, researchers at the Massachusetts Institute of Technology (MIT) have taken a massive step in quantum computing, developing an innovative interconnect device that paves the way for scalable, all-to-all communication between superconducting quantum processors.