Ground state correlation functions of the XY spin chain in a random transverse field

The single-body and anomalous (pair) correlation functions of Jordan-Wigner fermions in the ground state of a disordered XY chain are calculated. Disorder is introduced into this system as a site-dependent transverse field taken from a uniform distribution of fixed width and within the ferromagnetic phase. Results show that increasing the disorder strength by increasing the distribution width leads to a more rapid decay of correlations within the bulk.