2025/02/20 by Shailesh Chandrasekharan, Chandrasekharan, Shailesh, Rui Xian Siew +3 · 3 citations
Physics and Astronomy · #Quantum many-body systems #Cold Atom Physics and Bose-Einstein Condensates #Advanced Thermodynamics and Statistical Mechanics
paper · pdf · doi:10.48550/arxiv.2502.14175
Traditional SU(N) lattice gauge theories (LGTs) can be formulated using an orthonormal basis constructed from the irreducible representations (irreps) Vλ of the SU(N) gauge symmetry. On a lattice, the elements of this basis are tensor networks comprising dimer tensors on the links labeled by a set of irreps \λ_ℓ\ and monomer tensors on sites labeled by \λs\. These tensors naturally define a local site Hilbert space, Hgs, on which gauge transformations act. Gauss's law introduces an additional index αs = 1, 2, …, D(Hsg) that labels an orthonormal basis of the gauge-invariant subspace of Hgs. This monomer-dimer tensor-network (MDTN) basis, | \λs\,\λ_ℓ\,\αs\⟩, of the physical Hilbert space enables the construction of new qubit-regularized SU(N) gauge theories that are free of sign problems while preserving key features of traditional LGTs. Here, we investigate finite-temperature confinement-deconfinement transitions in a simple qubit-regularized SU(2) and SU(3) gauge theory in d=2 and d=3 spatial dimensions, formulated using the MDTN basis, and show that they reproduce the universal results of traditional LGTs at these transitions. Additionally, in d=1, we demonstrate using a plaquette chain that the string tension at zero temperature can be continuously tuned to zero by adjusting a model parameter that plays the role of the gauge coupling in traditional LGTs.