  We adopt the tight-binding mode-matching method to study the strain effect on
silicene heterojunctions. It is found that valley- and spin-dependent
separation of electrons cannot be achieved by the electric field only. When a
strain and an electric field are simultaneously applied to the central
scattering region, not only are the electrons of valleys K and K' separated
into two distinct transmission lobes in opposite transverse directions, but the
up-spin and down-spin electrons will also move in the two opposite transverse
directions. Therefore, one can realize an effective modulation of valley- and
spin-dependent transport by changing the amplitude and the stretch direction of
the strain. The phenomenon of the strain-induced valley and spin deflection can
be exploited for silicene-based valleytronics devices.
