Plasmon Excitations in the Electron Gas

Drude model plasma frequency, Lindhard dielectric function, and collective modes

Material Parameters

Probe

Derived Quantities

ω_p (eV)—
E_F (eV)—
k_F (nm⁻¹)—
v_F (×10⁶ m/s)—
r_s—

Drude: ε(ω)=ε_∞−ω_p²/(ω²+iγω)

Plasma freq: ω_p²=ne²/(ε₀m*)

Plasmon dispersion:

ω²(q) ≈ ω_p² + (3/5)v_F²q²

Particle-hole continuum:

ω ∈ [ℏ²|2k_F·q−q²|/(2m), ...]

Plasmon damps when entering
particle-hole continuum (Landau damping)