Flatbands in frustrated lattice <i>X</i>3MnN3 (<i>X</i> = Ca, Sr, Ba): A first-principles study

Frustrated lattices with dispersionless band structures and fully localized states are an exciting platform for exploring many-body physics. In this work, we identify X3MnN3 (X= Ca, Sr, Ba) as a frustrated lattice investigate its physical properties in the ferromagnetic (FM) antiferromagnetic (AFM) based on first-principles calculations. Our results show that all three materials FM A-type AFM configurations have flatbands touching kz∼0 kz∼π planes bandwidths less than 0.2 eV. Intriguingly, flatband is tuned to Fermi level when transformed into state. Furthermore, find two-dimensional dice model hidden by treating coupled Mn N atoms basic site, revealing compact state generated destructive interferences between hopping amplitudes, models stack system staggered along c-axis. work provides new candidate strong correlation physics reveals mechanism of their