4 papers
cond-mat.str-el2026
Diagrammatic Monte Carlo for Fermionic Rényi Entanglement Entropy
Boyuan Shi
We develop a direct diagrammatic Monte Carlo framework for the Renyi entanglement entropy of interacting lattice fermions. The method starts from the fermionic graded-swap represen…
cond-mat.str-el2025
CoS++: Towards More General and Explicit Implementations for Sampling High-Order Feynman Diagrammatic Series
Boyuan Shi
Diagrammatic Monte Carlo methods provide robust routines for accurate computations of correlated electronic systems in the thermodynamical limit. Recently, its versatility was exte…
cond-mat.str-el2025
Fast summation of fermionic Feynman diagrams beyond Bravais Lattices and on-site Hubbard interactions
Boyuan Shi
We designed new algorithms for summing bold-line Feynman diagrams in arbitrary channels, where it can be readily modified for bare interaction series as well. When applied to magne…
cond-mat.str-el2025
Semi-Deterministic and Stochastic Sampling of Feynman Diagrams with 1/N Expansions
Boyuan Shi
We introduce a family of (semi) bold-line series, assisted with expansions, with being the number of fermion flavours. If there is no additional $\m…