title: Photoinduced transition between conventional and topological insulators in two-dimensional electronic systems.
abstract: Manipulating the topological properties of insulators, encoded in invariants such as the Chern number and its generalizations, is now a major issue for realizing novel charge or spin responses in electron systems. We propose that a simple optical means, subjecting to a driving laser field with circular polarization, can be fruitfully incorporated to this end. Taking as a prototypical example the two-band insulator first considered by Haldane, we show how the electron system can be tuned through phases associated with different Chern numbers as the laser intensity is adiabatically swept, i.e., a photoinduced analog of the quantum Hall plateau transition. The implications of our findings include the possibility of laser tuning a conventional insulator into a quantum spin Hall system.
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan. INOUE.Junichi@nims.go.jp
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Inoue
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tanaka