REPORTS BY H.B. NERSISYAN AND CO-RESEARCHERS DESCRIBE RECENT ADVANCES IN PHYSICS

Science Letter
September 8, 2009

PHYSICS;

According to recent research published in the journal Physical Review
E, "The results of a theoretical investigation on the stopping
power of ions moving in a two-dimensional degenerate electron gas
are presented. The stopping power for an ion is calculated employing
linear-response theory using the dielectric function approach."

"The collisions, which lead to a damping of plasmons and quasiparticles
in the electron gas, is taken into account through a relaxation-time
approximation in the linear-response function. The stopping power for
an ion is calculated in both the low-and high-velocity limits. In
order to highlight the effects of damping, we present a comparison
of our analytical and numerical results, in the case of pointlike
ions, obtained for a nonzero damping with those for a vanishing
damping. It is shown that the equipartition sum rule first formulated
by Lindhard and Winther for three-dimensional degenerate electron
gas does not necessarily hold in two dimensions. We have generalized
this rule introducing an effective dielectric function. In addition,
some results for two-dimensional interacting electron gas have been
obtained," wrote H.B. Nersisyan and colleagues (see also Physics).

The researchers concluded: "In this case, the exchange-correlation
interactions of electrons are considered via local-field corrected
dielectric function.."

Nersisyan and colleagues published their study in Physical Review E
(Interaction of fast charged projectiles with two-dimensional electron
gas: Interaction and collisional-damping effects. Physical Review E,
2009;80(1 Part 2):6402).

For additional information, contact H.B. Nersisyan, Institute
Radiophys & Electrical, Division Theoret Physics, Alikhanian Bros
St. 1, Ashtarak 378410, Armenia.