Quantum size effects in free-standing MgB2 films

Using the full-potential Linearized Muffin-tin Orbital method, we calculate the electronic structure of free-standing MgB2 (0001) films with 2 to 10 Mg/B bilayers. Owing to the quantum size effects, the electron energy of the occupied quantum well states and the density of states at the Fermi level exhibit oscillatory behavior with the number of Mg/B bilayers. The incremental energy with the bilayer added and the quantum-well state energy are used to study the MgB2 film stability, suggesting the existence of the 'magic numbers' in film growth