Presentation Information
[P2-14]Terbium under High Pressure: First-Principles Density Functional Theory and Dynamical Mean-Field Theory Studies
*Cheng-Chien Chen1 (1. University of Alabama at Birmingham (United States of America))
Keywords:
Terbium Metal,High pressure,Density Functional Theory,Hubbard U,Dynamical Mean-Field Theory
Rare-earth metals serve as intriguing platforms for exploring emergent quantum phenomena. However, simulating these systems is challenging due to strong correlation effects. In this talk, we discuss two advanced first-principles methods—density functional theory with Hubbard U correction (DFT+U) and DFT plus dynamical mean-field theory (DFT+DMFT)—for studying terbium (Tb) metal under pressure. Specifically, we use linear-response approaches to determine the effective Hubbard U values of Tb in the pressure range 0-60 GPa [1]. Subsequent DFT+U calculations reveal distinct magnetic ground states in different high-pressure phases, with the magnetic propagation vectors in good agreement with experimental observations. A non-collinear spin configuration is also predicted for the high-pressure dhcp phase. Moreover, we employ fully charge self-consistent DFT+DMFT to study Tb’s electronic structure [2]. In the low-pressure hcp phase, our calculations show correlation-induced band renormalization and a temperature-induced ferromagnetic to paramagnetic transition. These results align well with the experiments. The computed electron density of states for the higher-pressure alpha-Sm and dhcp phases also serve as predictions for future spectroscopic measurements. Overall, our state-of-the-art first-principles calculations provide a robust framework for studying heavy lanthanides via advanced quantum many-body simulations. References Cited:[1] L. A. Burnett, M. P. Clay, Y. K. Vohra, C.-C. Chen, “First-Principles Calculation of Hubbard U for Terbium Metal under High Pressure”, J. Phys.: Condens. Matter 36, 425602 (2024). [2] W. Ding, Y. K. Vohra, C.-C. Chen, “Terbium under High Pressure: First-Principles Dynamical Mean-Field Theory Study”, arXiv:2412.16125 (2024). Funding Acknowledgment: This work is supported by the U.S. Department of Energy (DOE) Basic Energy Sciences Program under Award No. DE-SC0023268.
