American and European physicists have demonstrated a new way to predict whether metallic compounds are likely to host topological states arising from strong electron interactions.
Physicists from Rice University, leading the research and collaborating with physicists from Stony Brook University, Vienna University of Technology in Austria (TU Wien), Los Alamos National Laboratory, Spain’s Donostia International Physics Center and Germany’s Max Planck Institute for the Chemical Physics of Solids, revealed their design principle What’s new in a study published online today in Nature Physics.
The team includes scientists at Rice, Two Wayne and Los Alamos who discovered the first highly correlated topological semimetallic in 2017. This system and others, the new design principle seek to be widely identified by the quantum computing industry because topological states have immutable features. They can be erased or lost due to quantum decoherence.
Study co-author Qimiao Si, Harry C., and Olga K. Wiess, professor of physics and astronomy, said Olga K. Wiess. “We expect this work to help guide its exploration.”
In 2017, the CV Rice research group conducted a model study and found an astonishing state of matter that hosts both a topological character and a fundamental example of strong correlation physics called the Kondo effect, an interaction between the magnetic moments of bound electrons trapped in atoms in a metal and the collective coils of billions of passing conduction electrons. . At the same time, an experimental team led by Silke Paschen of TU Wien presented a new material and stated that it had the same properties as those of the theoretical solution. The two teams named the strongly bound state of matter Weyl-Kondo semimetal. C said crystal symmetry played an important role in the studies, but the analysis remained at the proof-of-principle level.
“Our work in 2017 focused on a hydrogen atom type of crystal symmetry,” said Sy, a theoretical physicist who has spent more than two decades studying highly bonded materials such as heavy fermions and unconventional superconductors. “But it paved the way for the design of new, linked metallic topologies.”
Strongly correlated quantum materials are those in which interactions of billions with billions of electrons give rise to collective behaviors such as unconventional superconductivity or electrons that behave as if their normal mass is more than 1,000 times. Although physicists have studied topological materials for decades, they have only recently begun to study topological minerals that host highly correlated interactions.
“Materials design is generally very difficult, and design of highly correlated materials is still difficult,” said Sy, a member of the Rice Quantum Initiative and director of the Rice Center for Quantum Materials (RCQM).
Jennifer Cano of Si and Stony Brook led a group of theorists who developed a framework for identifying promising candidate materials by cross-referencing information in a database of known materials with the output of theoretical calculations based on realistic crystal structures. Using the method, the group determined the crystal structure and elemental composition of three materials that were likely candidates to host topological states arising from the Kondo effect.
said Kano, associate professor of physics and astronomy at Stony Brook and research scientist at the Flatiron Institute’s Computing Center for Quantum Physics. “Our work is the first step in that direction.”
Sy said the predictive theoretical framework came from his and Kano’s realization following an impromptu discussion session they organized among their respective working groups at the Aspen Center for Physics in 2018.
“What we hypothesized is that the strongly correlated excitations are still subject to symmetry requirements,” he said. “Because of that, I can say a lot about the topology of the system without resorting to ab initio computations that are often required but especially challenging to study highly correlated materials.”
To test the hypothesis, theorists at Rice and Stony Brook conducted model studies of realistic crystal symmetries. During the pandemic, theory teams in Texas and New York have had intense virtual discussions with the Passion Experimental Group at TU Wien. The collaboration developed a design principle for topological semi-metallic materials interconnected with the same symmetries used in the studied model. The usefulness of the design principle was demonstrated by the Paschen team, who made one of the three specific vehicles, tested and verified that it hosts the expected characteristics.
“All the evidence suggests that we’ve found a powerful way to identify materials that have the features we want,” Sy said.
The study’s co-authors include: Li Chen, Chandan City, and Haoyu Hu of Rice; Rice graduate Sarah Greiff 17 from Los Alamos National Laboratory; Lukas Fischer, Shenlin Yan, Jako Iguchi and Andrey Prokofiev from TU Wien; and Maya Vergnori of the Max Planck Institute for the Chemical Physics of Solids in Dresden, Germany and the Donostia International Center for Physics in Donostia San Sebastian, Spain.
Research in Rice was supported by the Air Force Office of Scientific Research (FA9550-21-1-0356), the National Science Foundation (DMR-2220603, EIA-0216467, CNS-1338099, DMR-170109, PHY-1607611), the Welch Foundation ( C-1411) and the shared Rice University Network computing facilities, and benefited from the hospitality of the Aspen Center for Physics.