The Geophysical Laboratory's Postdoctoral Fellow Shi Liu was awarded the 2017 APS Metropolis Award in late October. The purpose of the award is to recognize doctoral thesis research of outstanding quality and achievement in computational physics and to encourage effective written and oral presentation of research results.
The award consists of $2,500 and a certificate to be presented at an awards ceremony at the Division of Computational Physics annual meeting and an additional allowance of up to $1,500 to travel to the meeting. Liu will be invited to present his work in an appropriate session of the meeting.
The thesis work of Liu focused on the development and application of predictive multiscale modeling techniques that combine methods at different length and time scales to understand the dynamics of ferroelectric materials from the atomic level all the way up to the mesoscopic length scales. One notable study is to understand the intrinsic polarization switching in ferroelectrics published in Nature in 2016. Shi started from first-principles calculations of ferroelectrics and then built model interatomic potentials enabling large-scale molecular dynamics simulations (up to 850,000 atoms). He then scaled the simulation up to the bulk material, considered as a continuous medium, within the framework of Landau-Ginzburg-Devonshire theory. This progressive theoretical framework allows for the first time an efficient and accurate estimation of macroscopic properties such as the coercive field for a broad range of ferroelectrics from first-principles. Liu is currently working with Dr. R. E. Cohen at the Geophysical Laboratory on multiscale simulations of defects in ferroelectrics. The goal is to understand how the presence of defects influences the properties of ferroelectrics and how to manipulate and optimize ferroelectric properties through defect engineering.
Liu will present an invited talk at the APS March Meeting in New Orleans, Louisiana, March 13-17, 2017, on “For development, and for application to the dynamics and thermal properties of ferroelectric materials, of innovative computational methodologies and theoretical models applicable to the physics of materials ranging from nano-to mesoscopic length scales.”
The above figure highlights Liu's thesis work:
Right: Simulated electric field-induced nucleation process at the domain wall.