Harris, A. BrooksAharony, AmnonEntin-Wohlman, OraKorenblit, I. YaBirgeneau, Robert JKim, Youngjune2023-05-232023-05-232001-06-222015-08-04https://repository.upenn.edu/handle/20.500.14332/43048Sr2Cu3O4Cl2 is an antiferromagnet consisting of weakly coupled CuO planes which comprise two weakly interacting antiferromagnetic subsystems I and II which order at respective temperatures TI≈390 K and TII≈40 K. Except asymptotically near the ordering temperature, these systems are good representations of the two-dimensional quantum spin-1/2 Heisenberg model. For TPhysicsQuantum PhysicsArticle