You take the blue pill... the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill... you stay in Wonderland, and I show you how deep the rabbit hole goes.
You take the blue pill... the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill... you stay in Wonderland, and I show you how deep the rabbit hole goes.
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EntanglementCFTFrom F. Pollmann, S. Mukerjee, A. M. Turner, and J. E. Moore, Phys. Rev. Lett. 102, 255701 (2009) (ArXiv link https://arxiv.org/abs/0812.2903v2), the central charge at a critical point can be determined from the scaling of the entropy or correlation length with respect to the number of states. Near (but not at) a critical point, the entanglement scales with the correlation length as {$$S = \frac{c}{6} \log \xi + a$$} where {$c$} is the central charge, and {$a$} is some non-universal boundary term. This is not a bad way to determine {$c$} for an iMPS. An MPS is driven off criticality by the finite basis size; the correlation length is cutoff by {$$\xi \propto m^\kappa$$} Hence this gives a relation for an MPS, {$$S = \frac{c \kappa}{6} \log m + \mbox{const}$$} Pollmann et al showed, making use of the Calibrese-Lefevre result for the distribution of the reduced density matrix spectra (Phys Rev A 78, 032329 (2008)), that this leads to a connection between correlation exponent {$\kappa$} and central charge {$c$}, {$$ \kappa \simeq \frac{6}{c + \sqrt{12c}} $$}
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