CAREER: Tuning Topology and Strong Correlations for the Next Generation of Topological Superconductors

University Of Chicago, Chicago IL

Investigators

Abstract

This award is funded in part under the American Rescue Plan Act of 2021 (Public Law 117-2). NON-TECHNICAL DESCRIPTION: A theoretically predicted quantum matter – a topological superconductor – not only conducts electricity with zero resistance but also protects its innate quantum properties from material imperfections. Experimentally realizing this new material is key to enabling future fault-tolerant quantum computers which can outperform classical computers by orders-of-magnitude. Yet, the existence of such materials remains elusive. This project supported by the Condensed Matter Physics program in the Division of Materials Research utilizes atomic-level layer-by-layer construction to fabricate new generations of topological superconductors, and performs advanced material characterizations to establish the evidence for this new state of matter. This project provides a substantial step forward to realize topological superconductors at temperatures achievable by industrial cryogenics. It can have profound impacts in not only condensed matter physics but also broadly in quantum science and engineering: new quantum computing architectures and protocols can be built on top of this material discovery. The research effort is integrated with an education and outreach theme “Immersive Quantum Material Education” to train students at graduate, undergraduate, and high-school levels. The research results are disseminated through dedicated activities such as the “UChicago Quantum Quickstart” workshop for 9th-to-11th grade students with demonstrated 34% participation from under-represented minority groups. Graduate students trained through this project can advance their careers in academia or in the emerging quantum engineering industry, forming the workforce for the future and ensuring the American leadership in both quantum sciences and quantum economy. TECHNICAL DESCRIPTION: Topological superconductors are a new class of superconductors predicted to enable fault-tolerant quantum computing. Current material platforms for putative topological superconductors are based on heterostructures of conventional superconductors and semiconductors, and require sophisticated engineering only to work at temperatures below 1 Kelvin. Yet, the conclusive test of topological superconductivity remains elusive. The goals of this project are three-fold: 1) performing atomic-level structural tuning of FeTeSe/oxides to optimize the topological electronic properties using molecular beam epitaxy; 2) performing femtosecond dynamical tuning of FeTeSe/oxides to reveal the relationship between topology and electron-electron interactions using time-resolved photoemission; 3) testing non-Abelian anyon statistics by fabricating topological quantum devices using molecular beam epitaxy with shadow masks. This project can substantially advance the field of topological materials by addressing the urgent questions on the existence and optimization of topological superconductors, and provide transformative insights into the relationship between topological superconductivity and strong electron-electron interactions. In the education and outreach theme “Immersive Quantum Material Education,” the principal investigator engages with students at all levels on the cutting-edge research on topological materials. Workshops such as the “MASTER Summer School” for undergraduate students and “Certificate in Quantum Engineering and Technology” for industrial workers promote awareness among the public on topological superconductivity, benefiting students from under-represented minority groups. The educational effort establishes the principal investigator’s laboratory as an anchor to facilitate general education on quantum science and engineering in South Side Chicago. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.