Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session E38: Quantum Many-Body Systems and Methods
8:00 AM–10:48 AM,
Tuesday, March 6, 2018
LACC Room: 501A
Sponsoring Unit: DCOMP
Chair: Lev Vidmar, Pennsylvania State Univ
Abstract: E38.00013 : Effective models for the low energy behavior of FeSe from first principles quantum Monte Carlo*
10:24 AM–10:36 AM
(Physics, Univ of Illinois - Urbana)
A major question in the study of iron-based superconductors is what appropriate effective model applies to them. Recently, it has become possible to use highly accurate fixed-node diffusion Monte Carlo (FN-DMC) calculations to derive effective models for correlated electron systems. Previous work by our group has shown that FN-DMC provides an accurate accounting of several properties of FeSe. We combine FN-DMC calculations with the model-fitting approach in  and a matching pursuit approach to quantify the importance of different interaction and hopping parameters to algorithmically select multiple minimal models for the low-energy degrees of freedom of the system using only first principles data. We will discuss these models and what they mean for the description of this system.  H. J. Changlani, H. Zheng, and L. K. Wagner, The Journal of Chemical Physics 143, 102814 (2015).  B. Busemeyer, M. Dagrada, S. Sorella, M. Casula, L. K. Wagner, Physical Review B 94, 035108 (2016).
*This work was supported by the Center for Emergent Superconductivity, funded by the U.S. Department of Energy (DEAC0298CH1088), and the Blue Waters sustained-petascale computing project (NSF awards OCI-0725070, ACI-1238993).
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