# The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

## Grassmann tensor-network method for strong-coupling QCD

Aug 10, 2022, 2:40 PM
20m
CP1-HSZ/1st-1.004 - HS7 (CP1-HSZ)

### CP1-HSZ/1st-1.004 - HS7

#### CP1-HSZ

70
Oral Presentation Algorithms (including Machine Learning, Quantum Computing, Tensor Networks)

### Speaker

Jacques Bloch (University of Regensburg)

### Description

We present a tensor-network method for strong-coupling QCD with staggered quarks at nonzero chemical potential. After integrating out the gauge fields at infinite coupling, the partition function can be written as a full contraction of a tensor network consisting of coupled local numeric and Grassmann tensors. To evaluate the partition function and to compute observables, we develop a Grassmann higher-order tensor renormalization group method, specifically tailored for this model. We apply the method to the two-dimensional case and validate it by comparing results for the partition function, the chiral condensate and the baryon density with exact analytical expressions on small lattices up to volumes of $4\times4$. For larger two-dimensional volumes, we present first tensor results for the chiral condensate as a function of the mass and volume, and observe that the chiral symmetry is not broken dynamically in two dimensions. We also present tensor results for the number density as a function of the chemical potential, which hint at a first-order phase transition.

### Primary authors

Jacques Bloch (University of Regensburg) Dr Robert Lohmayer (Leibniz Institute for Immunotherapy)