Entanglement crossover close to a quantum critical point

We discuss the thermal entanglement close to a quantum phase transition by analyzing the pairwise entanglement for one-dimensional models in the quantum Ising universality class. We demonstrate that the entanglement sensitivity to thermal and to quantum fluctuations obeys universal T ≠ 0-scaling laws. We show that the entanglement exhibits a peculiar universal crossover behaviour, shedding light on the mechanisms bringing quantum criticality up to finite temperatures.