title: Disorder-induced quantum bond percolation.
abstract: We investigate the effects of off-diagonal disorder on localization properties in quantum bond percolation networks on cubic lattices, motivated by the finding that the off-diagonal disorder does not always enhance the quantum localization of wavefunctions. We numerically construct a diagram of the 'percolation threshold', distinguishing extended states from localized states as a function of two degrees of disorder, by using the level statistics and finite-size scaling. The percolation threshold increases in a characteristic way on increasing the disorder in the connected bonds, while it gradually decreases on increasing the disorder in the disconnected bonds. Furthermore, the exchange of connected and disconnected bonds induced by the disorder causes a dramatic change of the percolation threshold.
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Nishino
authors.forename: Shuji
authors.initials: S
authors.lastname: Katsuno
authors.forename: Masaki
authors.initials: M
authors.lastname: Goda