RESPONSE FUNCTION OF THE 2D QUANTUM ELECTRON-SOLID

We study the static density response function of the 2D quantum electr on solid with analytic and quantum Monte Carlo techniques. The 'longit udinal' response function at small and intermediate momentum transfer from the simulation is well approximated by the analytic results using phonons alone, provided the Debye-Waller factor is included. The 'tra nsverse' response function and the large momentum transfer longitudina l response function from simulations are larger than the analytic resu lts from contributions with phonons alone.