A useful way to obtain the central charge of entanglement Hamiltonian -- Nested entanglement entropy

In this paper, we review how to obtain the central charge of a critical entanglement Hamiltonian through the nested entanglement entropy which was first introduced in [J. Lou et al. PRB 84, 245128 (2011)]. The critical phenomena of the entanglement Hamiltonian can be identified by the central charge obtained by the nested entanglement entropy. We review our previous studies[J. Lou et al. PRB 84, 245128 (2011), S. Tanaka et al. PRA 87, 214401 (2013)] in which we investigated certain entanglement nature of two-dimensional valence-bond-solid (VBS) state and quantum hard-square models on square and triangle ladders using the nested entanglement entropy.Comment: 5 pages, 3 figures, to appear in Interdisciplinary Information Science

On the anomalous superfluid hydrodynamics

It has been shown by Son and Sur\'owka that the presence of anomaly in hydrodynamics with global U(1) symmetry can induce vortical and magnetic currents. The induced current is uniquely determined by anomaly from the existence of an entropy current with non-negative divergence. In this work, we extended the analysis to hydrodynamics with U(1) symmetry spontaneously broken, i.e. U(1) superfluid hydrodynamics. We found that all possible first order gradient corrections are determined up to five arbitrary functions, with the entropy current containing one arbitrary function. Furthermore, the stress tensor does not receive correction from terms proportional to the magnetic field.Comment: 22 pages, missing terms included, with qualitative change of the result