We present a general theory of the corrections to the asymptotic behaviour of the Renyi entropies which measure the entanglement of an interval A of length L with the rest of an infinite one-dimensional system, in the case when this is described by a conformal field theory of central charge c. These can be due to bulk irrelevant operators of scaling dimension x>2, in which case the leading corrections are of the expected form L^{-2(x-2)} for values of n close to 1. However for n>x/(x-2) corrections of the form L^{2-x-x/n} and L^{-2x/n} arise and dominate the conventional terms. We also point out that the last type of corrections can also occur with x less than 2. They arise from relevant operators induced by the conical space-time singularities necessary to describe the reduced density matrix. These agree with recent analytic and numerical results for quantum spin chains. We also compute the effect of marginally irrelevant bulk operators, which give a correction (log L)^{-2}, with a universal amplitude. We present analogous results for the case when the interval lies at the end of a semi-infinite system.
A useful way to obtain the central charge of entanglement Hamiltonian -- Nested entanglement entropy
在本文中,我们回顾了如何通过嵌套纠缠熵获得临界纠缠哈密顿量的中心荷,这是在[J. Lou et al. PRB 84,245128(2011)]中首次引入的。由嵌套纠缠熵得到的中心荷可以识别纠缠哈密顿量的临界现象。我们回顾了我们以前的研究[J. Lou等人PRB 84,245128(2011),S. Tanaka et al. PRA 87,214401(2013)],其中我们使用嵌套纠缠熵研究了二维价键固体(VBS)态和正方形和三角形梯子上的量子硬正方形模型的某些纠缠性质。