Performance Portable $\mathrm{S}\mathrm{U}(N)$ Lattice Gauge Theory Simulation with Kokkos

The increasing diversity of high performance computing systems makes separate, architecture specific implementations of lattice gauge theory algorithms costly to maintain. We present $\mathtt{\text{kwqft}}$, a performance portable Kokkos implementation of Wilson pure gauge Monte Carlo simulation for $\mathrm{S}\mathrm{U}(N)$ Yang-Mills theory in an arbitrary number of space-time dimensions. The gauge group order $N$ and the dimension $D$ are compile time parameters. A single source targets the Serial, OpenMP, CUDA, HIP, and SYCL execution spaces, with MPI halo exchange overlapped with interior updates. The implementation reproduces the exact two-dimensional plaquette and published three and four dimensional values for gauge groups up to $\mathrm{S}\mathrm{U}(17)$. On an NVIDIA A100 the Kokkos CUDA backend is competitive with a native CUDA code, SIMD acceleration improves the OpenMP path on Armv9 processors, and a large scale speedup is demonstrated for an $\mathrm{S}\mathrm{U}(4)$ lattice on the LineShine supercomputer, currently ranked first on the TOP500 list.