Supersymmetry on a euclidean spacetime lattice 1. A target theory with four supercharges

We formulate a Euclidean spacetime lattice whose continuum limit is (2,2)supersymmetric Yang-Mills theory in two dimensions, a theory which possessesfour supercharges and an anomalous global chiral symmetry. The lattice actionrespects one exact supersymmetry, which allows the target theory to emerge inthe continuum limit without fine-tuning. Our method exploits an orbifoldconstruction described previously for spatial lattices in Minkowski space, andcan be generalized to more complicated theories with additional supersymmetryand more spacetime dimensions