Electronic structure
Which crystal-chemical and orbital conditions create a spatially distinct interstitial subspace near the Fermi level?
Research & results
Electronic structure and collective quantum behavior of the interstitial subsystem
The group combines first-principles electronic-structure calculations with methods designed for correlation, magnetism and low-dimensional materials. The goal is to identify microscopic mechanisms, not simply classify compounds.
Research & results
Research questions
Correlations
When do Coulomb interaction and hybridization drive spectral renormalization, local moments or a correlation-induced gap?
Magnetic order
How are interstitial moments and exchange pathways selected by orbital composition, dimensionality and confinement?
Control parameters
How do pressure, strain, layer number, stacking and interfaces reorganize the interstitial electronic subsystem?
Correlations and structural response
In calcium, Ca₂N, Ba₂N and mayenite, we investigate how local and non-local Coulomb interaction changes phase stability, band structure, localization and transport. The calcium study demonstrates why a many-body treatment can be decisive even when correlations are weak.
Localization mechanisms and low-energy descriptions
We use cavity-centered Wannier functions to describe interstitial quasi-atomic states, construct low-energy Hamiltonians and separate the role of hybridization from that of Coulomb interaction. This framework was applied to β-Yb₅Sb₃, Li₈Au, mayenite and BaF systems.
Magnetism of interstitial electrons
In β-Yb₅Sb₃, Li₈Au and layered fluoride systems, we resolve magnetic moments and ordering associated with the interstitial electronic subsystem. The comparison of related XF monolayers shows that the cation orbital content can determine whether a magnetic instability develops.
Confinement, layers and interfaces
Monolayers, bilayers and van der Waals heterostructures provide controlled settings for studying magnetism, Mott proximity and correlation-driven spectral changes. In BaF, the magnetic state changes from intralayer ferromagnetism in a monolayer to antiferromagnetic tendencies in confined bilayers and selected heterostructures.
Research & results
From structure to a correlated low-energy model
- 01
Structure and stability
Density-functional calculations, structural relaxation and phonon calculations establish candidate structures and test dynamical stability.
- 02
Electronic and orbital analysis
Band structures, projected states, electron localization and spin density reveal the interstitial subspace and its orbital origin.
- 03
Localized basis
Maximally localized Wannier functions centered in cavities provide a compact description of the relevant electride states.
- 04
Interactions beyond a band picture
DFPT or constrained-RPA estimates, DFT+U+V and DFT+DMFT treat local and intersite Coulomb interaction at different levels of detail.
- 05
Many-body diagnostics
Spectral functions, Hubbard-band transfer and imaginary-time spin correlations probe quasiparticle suppression and the formation of local moments.