Photo-induced Tomonaga-Luttinger-like liquid in a one-dimensional Mott insulator

2 July 2008 (Wed), 3:30 pm - 5:00 pm

8F large seminar room, Sengen site

Dr. Takashi Oka(岡隆史博士)

Department of Physics, University of Tokyo(東京大学大学院理学系研究科物理学専攻)

Photo-induced Tomonaga-Luttinger-like liquid in a one-dimensional Mott insulator

We theoretically study the non-equilibrium quantum phase transition in strongly correlated electron systemswhen strong AC electric fields are applied tothe Mott insulator.

The time-dependent density matrix renormalization group method is used to calculate the nonlinear optical conductivity for the half-filled one-dimensional Hubbard model, where we have found an emergence ofmetallic states that have a linear dispersion within the energy gap. This indicates that the photo-doped carriers behave collectively as in the Tomonaga-Luttinger liquid. A non-equilibrium phase diagram for the photo-induced insulator-to-metal transition is then proposed.

We further show that the numerical result is similar to an analytic result for an effective Dirac model, where the Floquet method is employed to incorporate the effect of strong electric fields.

Dr. Akihiro Tanaka(田中秋広）