Fingerprints of field-induced Berezinskii-Kosterlitz-Thouless transition in quasi-two-dimensional S=1/2 Heisenberg magnets Cu(en)(H2O)2SO4 and Cu(tn)Cl2
Keywords: Specific heat; Two-dimensional; Heisenberg square lattice; Berezinskii-Kosterlitz-Thouless transition;