Scaling of entanglement at a quantum phase transition for a two-dimensional array of quantum dots

Using the Hubbard model, the entanglement scaling behavior in a two-dimensional itinerant system is investigated. It has been found that, on the two sides of the critical point denoting an inherent quantum phase transition (QPT), the entanglement follows different scalings with the size, just as an order parameter does. This fact reveals the subtle role played by the entanglement in QPT as a fungible physical resource