Fig. 2: The results of temperature (T) dependence of high-pressure heat capacity (C) of SrCu2(BO3)2.
From: Deconfined quantum critical point lost in pressurized SrCu2(BO3)2
a, b are the plots of C/T versus T measured at 0.9 and 1.4 GPa, which show the typical characteristic of the dimmer singlet (DS) phase. The position of the maximum of the hump (TDS) signifies the formation temperature of the DS phase. (c–e display the pressure-induced two transitions upon cooling measured at 2.1, 2.5, and 2.6 GPa. The high-temperature peak relates to the plaquette-singlet liquid (PSL), while the low-temperature peak is associated with the plaquette-singlet phase (PS). The sharp PSL peak at 2.1 GPa relates to a critical point or a terminal point of phase boundary39. f, g are the results obtained at 2.7 and 2.75 GPa, respectively, illustrating the emergence of the antiferromagnetic (AF) phase. The insets show the transitions at low temperatures for a better view. h presents the results of C/T at 3.1 GPa, exhibiting an AF ground-state below TAF and an antiferromagnetic liquid phase below the crossover temperature TAFL.
