Liu, Fangze | Engineering Papers

DOE OSTI2024

Enhanced Pair-Density-Wave Vertices in a Bilayer Hubbard Model at Half Filling

Motivated by the pair-density-wave (PDW) state found in the one-dimensional Kondo-Heisenberg chain, we report on a determinant quantum Monte Carlo study of pair fields for a two-dimensional half-filled Hubbard layer coupled to an itinerant, noninteracting layer with one electron per site. In a specific range of interlayer hopping, the pairing vertex associated with PDW order becomes more attractive than that for uniform d-wave pairing, although both remain subdominant to the leading antiferromagnetic correlations at half filling. In conclusion, our result sheds light on where one potentially may find a PDW state in such a model.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2024

Self-supervised generative models for crystal structures

Not Available

36 MATERIALS SCIENCE↗

DOE OSTI2024

Emergence of antiferromagnetic correlations and Kondolike features in a model for infinite layer nickelates

We report a determinant quantum Monte Carlo study of a two-band model, inspired by infinite-layer nickelates, focusing on the influence of interlayer hybridization between $3d_{x^{2}-y^{2}}$ orbitals derived from Ni (or Ni and O) in one layer and rare-earth (R) 5d orbitals in the other layer, hereafter the Ni and R layers, respectively. For a filling with one electron shared between the two layers on average, interlayer hybridization leads to “self-doped" holes in the Ni layer and the absence of antiferromagnetic ordering, but rather the appearance of spin-density and charge-density stripe-like states. As the interlayer hybridization increases, both the Ni and R layers develop antiferromagnetic correlations, even though either layer individually remains away from half-filling. For hybridization within an intermediate range, roughly comparable to the intralayer nearest-neighbor hopping t Ni , the model develops signatures of Kondo-like physics.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗