KONDO EFFECT

Magnetic impurity in metal: spin screening, resistivity minimum, Kondo cloud
Kondo Physics

Anderson/Kondo (1964): single magnetic impurity (S=1/2) in metal generates antiferromagnetic exchange J

Kondo temperature:
T_K = D exp(-1/2Jρ)

Resistivity (3rd order in J):
ρ(T) = ρ₀[1 - 2Jρ ln(T/D)]

Below T_K: singlet screening cloud
ξ_K ~ ℏv_F / k_B T_K

T_K = —
Phase: —