Yusuke Nomura's Website

• So far, I have been involved in
• Symmetry adapted Wannier mode in Wannier90 (http://www.wannier.org)
• Constrained density-functional perturbation theory (for deriving electron-phonon coupled Hamiltonian)
• Estimation of interaction parameters tailored for dynamical mean-field solvers
• Implementation of dynamical mean-field solvers (CT-HYB and CT-INT)
• Double-expansion CT-HYB solver to treat retarded exchange interaction (dynamical J)
• Improvement of negative-sign problem in CT-INT by single-particle basis transformation and by efficient treatment of spin-flip and pair-hopping interactions
• Speed up (~ 10 times) of CT-INT solver by the introducing submatrix update

I am now involved in

• Machine-learning solvers to study many-body quantum systems
• RESPACK (https://sites.google.com/view/kazuma7k6r): open-source program for GW, constrained random phase approximation (cRPA), and maximally localized Wannier function
• Implementation of Trilex (independently from the original implementation of Ayral and Parcollet) and its extension to multi-orbital systems
• Development of efficient solver for electron-boson coupled Hamiltonian
• Efficient calculation of two-particle quantities using the idea of sparse modeling

I am also interested in

• Finite-temperature or time-dependent calculation using variational Monte Carlo technique

I use ab initio techniques to study these systems. So far, I have studied

• Alkali-doped fullerides and aromatic superconductors
• Iron-based superconductors
• Cuprate bulk and interface
• Honeycomb lattice iridate Na₂IraO₃
• Compressed sulfur hybrids H₂S and H₃S
• Transition metal oxide SrVO₃
• (111) bilayers of LaAuO₃ and SrIrO₃
• Organic conductor (TMTSF)₂PF₆

and so on…

In ongoing projects, I am studying

• Cuprates
• Alkali-doped fullerides
• Rare-earth nickelates RNiO₃
• Surface adatom systems
• 5d pyrochlore oxide Cd₂Os₂O₇
• Heavy-fermion compound LiV₂O₄

and so on…

I am interested in how phonons affect electrons and vice versa. For this purpose, I am interested in the development of more efficient/accurate solver for electron-boson coupled Hamiltonians.

I am especially interested in superconductivity realized in non-equilibrium situation.

• Band structure calculation (Quantum Espresso, Wien2k, ELK, …)
• Maximally localized Wannier function (Wannier90, Wien2Wannier, RESPACK): I have contributed to the development of version 2.1.0 of Wannier90
• Calculation of response function (e.g. dielectric function) from first principles (RESPACK)
• Phonon calculations using density-functional perturbation theory (Quantum Espresso)
• Ab initio derivation of realistic low-energy Hamiltonian
  • One-body part: Maximally localized Wannier function
  • Coulomb part: Constrained random phase approximation (cRPA)
  • Phonon part: Constrained density-functional perturbation theory (cDFPT)
• Machine learning using Boltzmann machines
• Variational Monte Carlo methods
• Dynamical mean-field theory with continuous-time quantum Monte Carlo method: I have implemented both CT-INT and CT-HYB from scratch
• Extension of DMFT (dynamical interaction, phonon, cellular DMFT, DCA, Trilex, …)
• RPA analysis of superconducting gap equation
• Fortran language, C language, Python (basic)
• Parallel computing (MPI and OpenMP)