Probing phase transition and underlying symmetry breaking via entanglement entropy scanning

Abstract: Entanglement takes a key role in quantum physics while how much information it can extract from many-body systems is still an open question, particularly for quantum criticalities and emergent symmetries. In this work, we systematically study the entanglement entropy (EE) and its derivative (DEE) near quantum phase transitions in various quantum many-body systems. An exact one-parameter scaling relation between the DEE and system size at the critical point has been derived for the first time, which successfully obtains the critical exponent via data collapse. What's more, we find that the EE peaks at the (emergent) symmetry-enhanced first-order transition which reflects higher symmetry breaking. This work provides a new paradigm for quantum many-body research from the perspective of EE and DEE.