Spin-glass properties of quasicrystals and complex metallic alloys

Spin-glass properties of magnetic quasicrystals with spins placed on a quasiperiodic lattice, and complex metallic alloys, characterized by giant unit cells, are reviewed. The systems exhibit rich variety of broken-ergodicity phenomena that share properties with site-disordered canonical spin glasses and site-ordered geometrically frustrated antiferromagnets. Magnetic frustration provides basis of a novel concept of digital data storage, where a byte of digital information can be stored into the material by pure thermal manipulation, in the absence of electric, magnetic or electromagnetic field.