Condensed Matter Seminar feat. Lubos Mitas: "Electronic structure quantum Monte Carlo: recent progress on spins and fixed-phase/node methods"
Lubos Mitas (NC State University)
I will talk about electronic structure quantum Monte Carlo (QMC) based on sampling of particle coordinates. The method has a broad appeal since it is applicable to electronic structure of real materials, including strongly correlated systems, as well as to ultracold condensates, model systems, etc. I will talk about recent developments on sampling fermion spins on the same footing as spatial variables, expanding thus the method to spin-orbit and other spin-dependent Hamiltonians. I will also touch on current understanding of fermion signs, in particular, on fixed-phase/node techniques and properties of fermion nodes that enable to reach accuracy up to ~ 99% of correlation energy in systems with hundreds of fermions.