Figure 3: Scaling laws of the derivative of contact with respect to the chemical potential in the quantum critical region.

The left panels show that different curves of , where
is the dimensionless chemical potential, near the transition V–P (a) and P–PP (b) intersect at the quantum critical point. The right panels show the collapse of
versus the temperature-scaled chemical potential
into a single curve. Results in both panels confirm the scaling laws predicted by equation (16). From the temperature-scaled contact at different temperatures, one reads off the the critical dynamic exponent z=2 and correlation length exponent ν=1/2.