Welcome to SpinGlassPEPS.jl, a open-source Julia package designed for heuristically solving Ising-type optimization problems defined on quasi-2D lattices and Random Markov Fields on 2D rectangular lattices.

The package SpinGlassPEPS.jl includes:

• SpinGlassTensors.jl - Package containing all necessary functionalities for creating and operating on tensors. It allows the use of both CPU and GPU.

• SpinGlassNetworks.jl - Package containing all tools needed to construct a tensor network from a given instance.

• SpinGlassEngine.jl - Package containing the solver itself and tools focused on finding and operating on droplets.

• Our goals

SpinGlassPEPS.jl was created to heuristically solve Ising-type optimization problems defined on quasi-2D lattices or Random Markov Fields (RMF) on 2D rectangular lattices. This package combines advanced heuristics to address optimization challenges and employs tensor network contractions to compute conditional probabilities to identify the most probable states according to the Gibbs distribution. SpinGlassPEPS.jl is a tool for reconstructing the low-energy spectrum of Ising spin glass Hamiltonians and RMF Hamiltonians. Beyond energy computations, the package offers insights into spin configurations, associated probabilities, and retains the largest discarded probability during the branch and bound optimization procedure. Notably, SpinGlassPEPS.jl goes beyond ground states, introducing a unique feature for identifying and analyzing spin glass droplets — collective excitations crucial for understanding system dynamics beyond the fundamental ground state configurations.