  The thermodynamics of excited nuclear systems allows one to explore the
second-order phase transition in a two-component quantum mixture. Temperatures
and densities are derived from quantum fluctuations of fermions. The pressures
are determined from the grand partition function of Fisher's model. Critical
scaling of observables is found for systems which differ in neutron to proton
concentrations thus constraining the equation of state of asymmetric nuclear
matter. The derived critical exponent {\beta}= 0.35 \pm 0.01, belongs to the
liquid-gas universality class. The critical compressibility factor Pc /{\rho}c
Tc increases with increasing neutron number.
