Local Electron Correlations in a Two-Dimensional Hubbard Model on the Penrose Lattice

Hideo Hasegawa

Nayuta Takemori, Akihisa Koga

We study electron correlations in the half-filled Hubbard model on two-dimensional Penrose lattice. Applying the real-space dynamical mean-field theory to large clusters, we discuss how low-temperature properties are affected by the quasiperiodic structure. By calculating the double occupancy and renormalization factor at each site, we clarify the existence of the Mott transition. The spatially-dependent renormalization characteristic of geometrical structure is also addressed.

Nayuta Takemori, Akihisa Koga, Hartmut Hafermann

We develop a real-space extension of the dual fermion approach. This method is formulated in terms of real-space Green's functions and local vertex functions, which enables us to discuss local and nonlocal correlations in inhomogeneous systems with an arbitrary geometric structure. We first demonstrate that the approach gives us reasonable results for a homogenous periodic system by taking into account onsite and nearest-neighbor intersite correlations. Moreover, we study the half-filled Hubbard model on the quasiperiodic Penrose lattice and clarify the role of intersite correlations for the Mott transition. The intersite correlations lead to a rich structure in local observables which is inherited from the quasiperiodic structure of the lattice.

Arisato Kawabata

Stefano Longhi

In the framework of the Hubbard model, it is shown that approximate dynamic localization for strongly correlated electrons hopping on a one-dimensional lattice and driven by a high-frequency sinusoidal field can be realized provided that periodic π phase slips are impressed into the sinusoidal field. A possible experimental demonstration of the proposed driving scheme is presented for a photonic model system of the two-particle Hubbard model, based on light transport in a square waveguide lattice with a sinusoidally curved optical axis.

H. A. Razafimandimby