Solution of the fermionic entanglement problem with interface defects
arXiv:1005.2144 · doi:10.1002/andp.201000055
Abstract
We study the ground-state entanglement of two halves of a critical transverse Ising chain, separated by an interface defect. From the relation to a two-dimensional Ising model with a defect line we obtain an exact expression for the continuously varying effective central charge. The result is relevant also for other fermionic chains.
15 pages, 6 figures, changed title and minor modifications in published version