Seminarium Fizyki Materii Skondensowanej

Variational wave functions constitute a precious tool for the study of frustrated spin models, which represent a formidable challenge for most numerical methods. In this talk, we discuss how magnetic and nonmagnetic phases of spin systems can be described by Gutzwiller-projected fermionic wave functions. In addition to ground state properties, we describe a variational approach to compute dynamical spectra by means of suitable Ansätze for excited states. The analysis of the dynamical structure factor of frustrated systems allows us to show how gapless spin liquids can "disguise themselves" on cylindrical geometries.