To understand correlated quantum materials, we develop new theoretical concept, advanced method and better algorithm. For our recent efforts, see:
"Frozen spin ratio and the detection of Hund correlations", Phys. Rev. Research (2023)
"DFT+DMFT with natural atomic orbital projectors", Phys. Rev. B (2019)
"Maximum Quantum Entropy Method", Phys. Rev. B (2018)
"Analytic continuation via domain-knowledge-free machine learning", Phys. Rev. B (2018)
"Quantified degeneracy and metal-insulator transition in complex transition-metal oxides", Phys. Rev. B (2018)
"The effect of double counting, spin density, and Hund interaction in the different DFT+U functionals", Sci. Rep. (2018)
"Calculating branching ratio and spin-orbit coupling from first-principles: A formalism and its application to iridates", Phys. Rev. B (2016)
Our material research covers a wide range of quantum materials and phenomena including high-temperature superconductors, Hund metal and other correlated metallic phases, Kondo and heavy fermion systems, correlated electrons at the interface, large spin-orbit coupling materials, magnetic and topological materials, etc.
Code and Software
Since 2002 we have been participating the development of DFT software package 'OpenMX (Open source package for Material explore)'. This pseudopotential local-basis code has been developed through international collaboration and under main supervision of Prof. Ozaki at ISSP, University of Tokyo. Our main interests and contributions are in the methods for correlated electronic structure and magnetism.
Jx code conducts magnetic force calculations with DFT solutions as the input. It supports both collinear and non-collinear spin Hamiltonian. For the former, our implementation details can be found in
"Jx: An open-source software for calculating magnetic interactions based on magnetic force theory" Comp. Phys. Comm. 247, 106927 (2020).
See also,
"Reliability and applicability of magnetic force linear response theory: Numerical parameters, predictability and orbital resolution" Phys. Rev. B 97, 125132 (2018).
DMFT-pack is to perform DFT+DMFT calculations mainly with full-band OpenMX Hamiltonian. The code utilizes CT-QMC DMFT solvers together with the internal semi-empirical ones. It is armed with its own unique Natural-Atomic-Orbital projector and Maximum-Quantum-Entropy analytical continuation algorithm. For more details, see:
"DFT+DMFT with natural atomic orbital projectors", Phys. Rev. B (2019)
"Maximum Quantum Entropy Method", Phys. Rev. B (2018).
Kai-EDJ is to conduct DMFT and MFT calculations in a separate or combined mode. It provides its own internal ED-DMFT solver and the interface to the external CT-QMC solvers. For magnetic force theory, Kai-EDJ runs by itself being separated from Jx. At this moment, only collinear MFT is supported. For more details, see:
"KaiEDJ: A program conducting dynamical mean-field theory and magnetic force theory calculation for correlated magnetic materials", (under review)
Fundings