The stability of germanene under biaxial tensile strain and the accompanying
modifications of the electronic properties are studied by density functional
theory. The phonon spectrum shows that up to 16% strain the germanene
lattice is stable, where the Dirac cone shifts towards higher energy and
hole-doped Dirac states are achieved. The latter is due to weakening of the
Ge-Ge bonds and reduction of the s-p hybridization. Our calculated Gr\"uneisen
parameter shows a similar dependence on the strain as reported for silicene
(which is different from that of graphene).Comment: 11 pages, 3 figures, and 1 Tabl
