Quantum Transport in One-Dimensional Doped Mott Insulator(ドープされた1次元モット絶縁体の量子輸送現象)

Takashi Oka, Ryotaro Arita, Hideo Aoki

Alexander van Oudenaarden, Johan E. Mooij

The quantum transport of vortices in very long and narrow arrays of small Josephson junctions has been studied experimentally. The chemical potential of the system can be changed by an external magnetic field. When the vortex density is commensurate with the one-dimensional junction lattice, the vortex mobility vanishes for a finite window of the magnetic field. The localization of the vortices is due to the forming of a one-dimensional Mott insulator.

Vadim V. Ponomarenko, Naoto Nagaosa

Markus Garst, Achim Rosch

We study numerically how conservation laws affect the optical conductivity σ(ω) of a slightly doped one-dimensional Mott insulator. We investigate a regime where the average distance between charge excitations is large compared to their thermal de Broglie wavelength and a classical description is possible. Due to conservation laws, the dc conductivity is infinite and the Drude weight D is finite even at finite temperatures. Our numerical results test and confirm exact theoretical predictions for D both for integrable and non-integrable models. Small deviations from integrability induce slowly decaying modes and, consequently, low-frequency peaks in σ(ω), which can be described by a memory matrix approach.

Zheng-Yu Weng, Y. L. Zhou, V. N. Muthukumar

Xixiao Ma, Yu Lan, Ling Qin +1 more

Within the framework of the fermion-spin theory, the charge transport in the doped Mott insulators on a honeycomb lattice is studied by taking into account the pseudogap effect. It is shown that the conductivity spectrum in the low-doped regime is separated by the pseudogap into a low-energy non-Drude peak followed by a broad mid-infrared band. However, the decrease of the pseudogap with the increase of doping leads to a shift of the position of the mid-infrared band towards the low-energy non-Drude peak, and then the low-energy Drude behavior recovers in the high-doped regime. The combined results of both the doped honeycomb-lattice and square-lattice Mott insulators indicate that the two-component conductivity induced by the pseudogap is a universal feature in the doped Mott insulators.