Spectroscopic Investigations of Molecular Quantum Materials. Probing Spin-Phonon Couplings and Intermolecular Magnetic Interactions

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

In this project, funded by the Chemical Structure, Dynamics & Mechanism B Program of the Chemistry Division, Professor Ziling Xue of the Department of Chemistry at the University of Tennessee is investigating molecular quantum materials with potential applications in ultra-high density data storage, quantum computation, and cryogenic magnetic refrigeration. Such materials are expected to have much larger storage capacities than the current storage materials, potentially leading to much more efficient computers and refrigeration devices. The specific goal of this project is to probe properties of the materials to identify the factors responsible for their performance. The project is interdisciplinary, covering inorganic, physical, and materials chemistries. It offers students unusual opportunities to conduct research at a national laboratory, which serves to broaden their educational background and training. The PI also works to attract high school students to consider pursuing studies in science with a particular emphasis on potential first generation college students from low income families . Slow magnetic relaxation is a critical property in applications related to molecular quantum materials. Current research efforts have been mostly focused on the design and preparation of compounds with large anisotropies and slow relaxation. There is relatively little understanding of the nature of spin-phonon couplings and intermolecular magnetic interactions, which are also main factors contributing to magnetic relaxation. In this project, molecular quantum materials will be studied using several unconventional spectroscopies to answer the following questions: (i) Can four-dimensional (4D) inelastic neutron scattering (INS) reveal spin-phonon coupling in molecular compounds? (ii) Can a magnetic peak’s unique dependence on the neutron scattering vector in INS be used to probe intermolecular magnetic interactions? (iii) To what degree can the combined use of far-infrared (IR), Raman, high-field electron paramagnetic resonance (EPR), pulsed EPR, and INS be used to study spin-phonon coupling? (iv) What are unique spin-spin relaxation properties are needed to develop effective quantum bits (qubits)? Progress in addressing these fundamental questions is expected to be an important step in the effort of the chemistry to develop new systems that have the potential to serve as quantum bits for quantum computing or related quantum materials applications. 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.