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.
Tools /
MpISpectrum
For simple uses, use By default, The eigenvalue d is related to the correlation length as correlation_length_per_unit_cell = -1 / ln(|d|) To get the correlation length per site, multiply by the unit cell size. If the wavefunction is parity symmetric, then the transfer operator is Hermitian and the eigenvalues will be purely real. An imaginary component means that parity symmetry is broken, which may occur either if the Hamiltonian was not parity symmetric to begin with (eg, the Kagome strip), or if the parity symmetry breaks spontaneously, eg due to a long-range chiral order. This is all that is required for simple uses. |