Speaker
Description
In this talk, I introduce the first open-source functional
renormalization group (FRG) code for condensed matter systems: divERGe.
The development of flexible and accessible computational frameworks is
becoming increasingly important as modern condensed matter problems
continue to grow in complexity, spanning from minimal theoretical
models to realistic descriptions of quantum materials. divERGe is
designed to bridge this gap by providing a versatile platform for
implementing and applying FRG approaches across a broad range of
systems.
I will highlight the general structure of the code, its modular design,
and key interface considerations that enable efficient adaptation to
different physical problems and computational workflows. Particular
emphasis will be placed on how divERGe facilitates studies beyond
conventional single-band models, including multi-orbital and multi-
sublattice systems, as well as applications incorporating fully first-
principles-derived material parameters. This allows for a systematic
investigation of competing electronic instabilities and emergent phases
in increasingly realistic settings.
The talk will further showcase several recent applications
demonstrating the capabilities of the framework. Notable use cases
include the prediction of unconventional chiral p/d-wave
superconductivity in twisted bilayer WSe₂, the identification of nearly
nodeless extended s-wave superconductivity in twisted bilayer SnSe₂,
and the electronic origin of Pomeranchuk order in a Ti-based Kagome
metal. These examples illustrate how modern FRG techniques can provide
valuable insights into the mechanisms driving unconventional quantum
phenomena in complex materials.