We show the positivity or negativity of truncated correlation functions in the quantum XY model with spin 1/2 (at any temperature) and spin 1 (in the ground state). These Griffiths–Ginibre inequalities of the second kind generalise an earlier result of Gallavotti.
|Number of pages||10|
|Journal||Journal of Statistical Physics|
|Early online date||11 Jul 2016|
|Publication status||Published - Sep 2016|