Compressibility sum rule for the two-dimensional electron gas.
The authors establish formulas for the isothermal compressibility and long-wavelength static density-density response function of a weakly correlated two-dimensional electron gas in the 1<<beta epsilon(F)<infinity and 0< or =beta epsilon(F)<<1 degeneracy domains; beta epsilon(F)=pi n Planck's over 2 pi(2)/(mk(B)T). The calculation of the pressure in the former domain is based on the Isihara-Toyoda formula [A. Isihara and T. Toyoda, Phys. Rev. B 21, 3358 (1980)] for the exchange-correlation energy at finite temperature. The pressure calculation in the latter domain is based on the Totsuji classical cluster-expansion formula for the correlation energy [H. Totsuji, J. Phys. Soc. Jpn. 40, 857 (1976); Phys. Rev. A 19, 889 (1979)].
Das
M P
MP
Department of Theoretical Physics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra ACT 0200, Australia.
Golden
K I
KI
Green
F
F