Heat capacity of a condensed electron system in the dilute metaln-Hg0.8Cd0.2Te

The magnetic-field–induced Wigner condensation was studied as a function of the electron temperature. Evaluating energy relaxation time and transport measurements we have determined the heat capacity of electrons in n-${\mathrm{Hg}}_{0.8}$ ${\mathrm{Cd}}_{0.2}$Te. As far as we know, this procedure yields the first experimental data of the heat capacity of a condensed, low-density electron system (n≊${10}^{14}$ electrons/${\mathrm{cm}}^3$). The data revealed a transition of the electron gas to a liquidlike state and eventually to a solidlike state with decreasing temperature.