TY  - JOUR
A1  - Zhang, Xin
A1  - Wu, Wei
A1  - Li, Gang
A1  - Wen, Lin
A1  - Sun, Qing
A1  - Ji, An-Chun
T1  - Phase diagram of interacting Fermi gas in spin-orbit coupled square lattices
JF  - New Journal of Physics
N2  - The spin-orbit (SO) coupled optical lattices have attracted considerable interest. In this paper, we investigate the phase diagram of the interacting Fermi gas with Rashba-type spin-orbit coupling (SOC) on a square optical lattice. The phase diagram is investigated in a wide range of atomic interactions and SOC strength within the framework of the cluster dynamical mean-field theory (CDMFT). We show that the interplay between the atomic interactions and SOC results in a rich phase diagram. In the deep Mott insulator regime, the SOC can induce diverse spin ordered phases. Whereas near the metal-insulator transition (MIT), the SOC tends to destroy the conventional antiferromagnetic fluctuations, giving rise to distinctive features of the MIT. Furthermore, the strong fluctuations arising from SOC may destroy the magnetic orders and trigger an order to disorder transition in close proximity of the MIT.
KW  - ultracold
KW  - hubbard-model
KW  - physics transition
KW  - metal-insulator transition
KW  - cluster dynamical mean-field theory
KW  - atomic gases
KW  - mean-field theory
KW  - mott insulator
KW  - optical lattice
KW  - weak ferromagnetism
KW  - quantum gases
KW  - superfluid
KW  - spin-orbit coupling
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151475
VL  - 17
IS  - 073036
ER  - 
TY  - JOUR
A1  - Li, Gang
A1  - Yan, Binghai
A1  - Thomale, Ronny
A1  - Hanke, Werner
T1  - Topological nature and the multiple Dirac cones hidden in Bismuth high-Tc superconductors
JF  - Scientific Reports
N2  - Recent theoretical studies employing density-functional theory have predicted BaBiO\(_{3}\) (when doped with electrons) and YBiO\(_{3}\) to become a topological insulator (TI) with a large topological gap (~0.7 eV). This, together with the natural stability against surface oxidation, makes the Bismuth-Oxide family of special interest for possible applications in quantum information and spintronics. The central question, we study here, is whether the hole-doped Bismuth Oxides, i.e. Ba\(_{1-X}\)K\(_{X}\)BiO\(_{3}\) and BaPb\(_{1-X}\)Bi\(_{X}\)O\(_{3}\), which are "high-Tc" bulk superconducting near 30 K, additionally display in the further vicinity of their Fermi energy E\(_{F}\) a topological gap with a Dirac-type of topological surface state. Our electronic structure calculations predict the K-doped family to emerge as a TI, with a topological gap above E\(_{F}\). Thus, these compounds can become superconductors with hole-doping and potential TIs with additional electron doping. Furthermore, we predict the Bismuth-Oxide family to contain an additional Dirac cone below E\(_{F}\) for further hole doping, which manifests these systems to be candidates for both electron-and hole-doped topological insulators.
KW  - localized wannier functions
KW  - total energy calculations
KW  - phase transitions
KW  - insulator
KW  - BaPb\(_{1-X}\)Bi\(_{X}\)O\(_{3}\)
KW  - temperature
KW  - system
KW  - wave basis set
KW  - initio molecular dynamics
KW  - diffraction
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148569
VL  - 5
IS  - 10435
ER  -