Hyowon Park
Physicist Hyowon Park, assistant professor at the University of Illinois at Chicago and Argonne joint scientist in the Material Science Division, will discuss his Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, Nov. 8, 2016.
“The DFT+DMFT Study of Energetics in Strongly Correlated Materials: Application to the Spin-state Transition in LaCoO3” will begin at 12:30 p.m. in Bldg. 203, Room D-120. All are welcome to attend.
Total energy calculations of materials are important for the theoretical study of phase transitions, atomic force/phonon calculations and also for the prediction of novel electronic/structural phases. Density functional theory (DFT) has been one of the successful first-principles methods and is widely used for computing energetics of various materials. Strongly correlated materials such as transitional metal oxides exhibit novel structural, electronic and magnetic properties whose first-principles study requires a theoretical description that goes beyond DFT to treat the strong correlation effects properly. The density functional theory plus dynamical mean field theory (DFT+DMFT) method can treat the strong dynamical correlation effect exactly and enables realistic calculations of those novel properties.
However, DFT+DMFT has been mostly applied to the calculation of spectroscopic quantities in strongly correlated materials. In his talk, Park will show that DFT+DMFT can be applied for the computation of the energetics in the subtle spin-state transition occurring at LaCoO3. The origin of the spin-state transition in this material has been controversial for almost 60 years and our DFT+DMFT energy calculations provide compelling evidence that the transition occurs from the low-spin state to the mixed spin-state of low-spin and high-spin. Park will also explain the importance of choosing the appropriate double-counting energy in DFT+DMFT to obtain quantitatively accurate energetics in this material. Finally, he will show how to implement atomic force calculations within DFT+DMFT and discuss future applications of DFT+DMFT to the study of structural properties in strongly correlated materials.
Hyowon Park is an assistant professor in the Department of Physics at the University of Illinois at Chicago and a joint scientist in the Material Science Division at the Argonne National Laboratory. Prior to joining Argonne, Park was a postdoctoral researcher at Columbia University working with Prof. Andrew Millis and Prof. Chris Marianetti. Park obtained his Ph.D. in physics at Rutgers University under the supervision of Prof. Kristjan Haule and Prof. Gabriel Kotliar.