The concurrence is an example of a class of functions that quantify this property, its namesake “monotones.” The bond dimension quantifies the extent of this property in tensor networks, such as the 1D MPS and higher-dimensional P·E·P·S. Area laws state that the “entropy” of this property grows with the size of the boundary between subsystems. States have this property if they cannot be decomposed as a sum of (*) product states. Applying a Hadamard gate followed by a C·NOT gate produces a pair of qubits (“Q-bits”) with this property called a Bell state. This (10[1])property (10[1])appears to allow information to travel faster than light (10[1])in the EPR paradox. For 10 points, name this property possessed by two quantum states that cannot be described independently, which Einstein called “spooky action at a distance.” ■END■