Low temperature resonances in the electron heat capacity of finite systems

Abstract

Temperature variations of the heat capacity ( C ) are studied in a low temperature regime T < δ F ∼ ε F / N for 2 D and 3 D systems with N ∼ 10 2 – 10 4 treated as a canonical ensemble of N -noninteracting fermions. The analysis of C is performed by introducing the function φ ( ε ) , the spectral distribution of C , that gives the contribution of each single-particle state to C . This function has two peaks divided by the energy interval Δ ε ≈ ( 2 – 5 ) T . If at some temperature T r e s a resonance takes place i.e. the positions of these peaks coincide with energies of two levels nearest to ε F then C vs T can show a local maximum at T r e s . This gives us the possibility to assess the single-particle level spacings near the Fermi level.