Thermodynamics of the<i>d</i> = 3 + 1 quantum<i>XY</i>model
Thermodynamics of the<i>d</i> = 3 + 1 quantum<i>XY</i>model
Within effective field theory we explore the properties of the $d$=3+1 quantum XY model at low temperatures and in weak magnetic or staggered fields. For this parameter regime only few results appear to be known, and furthermore are restricted to one-loop order. In the present study we systematically analyze the …