DIELECTRIC RESPONSE FUNCTION AND STOPPING POWER OF A 2-DIMENSIONAL ELECTRON-GAS

The dielectric response function of an electron ps confined in two dim ensions is calculated in the random-phase approximation at any degener acy. We then focus our attention on the stopping power of such an elec tron gas. The results exhibit important discrepancies with respect to the three-dimensional case. The leading term of the asymptotic expansi on in the high-velocity V range is independent of the electron mass an d decreases as 1/V.