  Electron spin relaxation in nanowire-based quantum dots induced by confined
phonons is investigated theoretically. Due to the one-dimensional nature of the
confined phonons, the van Hove singularities of the confined phonons and the
zero of the form factor of the electron-phonon coupling can lead to unique
features of the spin relaxation rate. Extremely strong spin relaxation can be
obtained at the van Hove singularity. Meanwhile the spin relaxation rate can
also be greatly suppressed at the zero of the form factor. This unique feature
indicates the flexibility of nanowire-based quantum dots in the manipulation of
spin states. It also offers a way to probe the property of the confined
phonons.
