  We introduce a notion of s-holomorphicity suitable for certain quantum spin
systems in one dimension, and define two observables in the critical
transverse-field Ising model which have this property. The observables are
defined using graphical representations in the complex plane, and are analogous
to Smirnov's FK-Ising and spin-Ising observables, respectively. We also briefly
discuss scaling-limits of these observables.
