Low temperature resonances in the electron heat capacity and its spectral distribution in finite systems.
Temperature variations of the heat capacity (C) are studied in a low temperature regime T < �F ∼ "F/N for 2D-, and 3D-systems with N ∼ 10 2 ÷ 10 4 treated as a canonical ensemble of N-noninteracting fermions. The analysis of C is performed by introducing function '("), 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 �" ≈ (2 ÷ 5)T. If at some temperature Tres there takes place a resonance i.e. the positions of these peaks coincide with energies of two levels nearest to "F then C vs T can show a local maximum at Tres. This gives possibility to assess the single-particle level spacings near the Fermi level.