Band structure and ballistic conductance of strained Si nanowires

The electronic band structure of hydrogen passi-vated, square cross-section, uniaxially strained [001], [110] and [111] silicon nanowires (Si NWs) has been calculated using nonlocal empirical pseudopotentials. Local pseudopotentials for bulk Si - calibrated to yield the correct workfunction and coupled to nonlocal corrections - yield results in good agreement with those of first-principles calculations, whenever available, and have been employed to calculate the electronic structure, the ballistic conductance and the effective mass of Si NWs, their dependence on wire diameter and strain and the corresponding variations of the band gap. We find the largest ballistic electron conductance for larger-diameter [001] wires under compressive strain while the smallest transport electron effective mass is found for larger-diameter [110] wires under tensile strain.