Hal Tasaki is a Professor at Physics Department of Gakushuin University, Japan. He obtained his PhD in physics from the University of Tokyo in 1986. He joined the group of Elliott Lieb in Princeton University as a posdoc (1986-1988) and he studied on quantum spin systems, which resulted in the now famous Affleck-Kennedy-Lieb-Tasaki (AKLT) theory. In 1995, he established the existence of ferromagnetism in a nonsingular Hubbard model. In 1997 he received the Ryogo Kubo memorial prize for his contribution to the study of quantum many-body systems. His interests also include non-equilibrium statistical mechanics and the foundations of equilibrium statistical mechanics.