Fractals are a never-ending pattern that you can zoom in on, and the image doesn’t change. Fractals can occur in two dimensions, like frost on a window, or in three dimensions, like tree limbs. A recent discovery from Purdue University researchers has established that superconducting images, seen above in red and blue, are actually fractals that fill a three-dimensional space and are disorder driven rather than driven by quantum fluctuations as expected. Frost and tree images by Adobe. Superconducting image (center) from "Critical nematic correlations throughout the superconducting doping range in Bi2-xPbzSr2-yLayCuO6+x" in Nature Communications. Credit: Nature Communications (2023). DOI: 10.1038/s41467-023-38249-3
Topics: Applied Physics, Civilization, Computer Modeling, Condensed Matter Physics, Materials Science, Solid-State Physics, Superconductors
Meeting the world's energy demands is reaching a critical point. Powering the technological age has caused issues globally. It is increasingly important to create superconductors that can operate at ambient pressure and temperature. This would go a long way toward solving the energy crisis.
Advancements with superconductivity hinge on advances in quantum materials. When electrons inside quantum materials undergo a phase transition, the electrons can form intricate patterns, such as fractals. A fractal is a never-ending pattern. When zooming in on a fractal, the image looks the same. Commonly seen fractals can be a tree or frost on a windowpane in winter. Fractals can form in two dimensions, like the frost on a window, or in three-dimensional space, like the limbs of a tree.
Dr. Erica Carlson, a 150th Anniversary Professor of Physics and Astronomy at Purdue University, led a team that developed theoretical techniques for characterizing the fractal shapes that these electrons make in order to uncover the underlying physics driving the patterns.
Carlson, a theoretical physicist, has evaluated high-resolution images of the locations of electrons in the superconductor Bi2-xPbzSr2-yLayCuO6+x (BSCO) and determined that these images are indeed fractal and discovered that they extend into the full three-dimensional space occupied by the material, like a tree filling space.
What was once thought of as random dispersions within the fractal images are purposeful and, shockingly, not due to an underlying quantum phase transition as expected but due to a disorder-driven phase transition.
Carlson led a collaborative team of researchers across multiple institutions and published their findings, titled "Critical nematic correlations throughout the superconducting doping range in Bi2-xPbzSr2-yLayCuO6+x," in Nature Communications.
The team includes Purdue scientists and partner institutions. From Purdue, the team includes Carlson, Dr. Forrest Simmons, a recent Ph.D. student, and former Ph.D. students Dr. Shuo Liu and Dr. Benjamin Phillabaum. The Purdue team completed their work within the Purdue Quantum Science and Engineering Institute (PQSEI). The team from partner institutions includes Dr. Jennifer Hoffman, Dr. Can-Li Song, Dr. Elizabeth Main of Harvard University, Dr. Karin Dahmen of the University of Illinois at Urbana-Champaign, and Dr. Eric Hudson of Pennsylvania State University.
Researchers discover superconductive images are actually 3D and disorder-driven fractals, Cheryl Pierce, Purdue University, Phys.org.