Quantal phases, disorder effects and superconductivity in spin-Peierls systems

In view of recent developments in the investigation on cuprate high-T${}{\rm c}$superconductorsandthespin-PeierlscompoundCuGeO${}{3}$, we study the effect of dilute impurity doping on the spin-Peierls state in quasi-one dimensional systems. We identify a common origin for the emergence of antiferromagnetic order upon the introduction of static vacancies, and superconductivity for mobile holes.