We discuss the nuclear magnetic relaxation rate and the superfluid density with the use of the effective five-band model by Kuroki et al. [Phys. Rev. Lett. 101, 087004 (2008)] in Fe-based superconductors. We show that a fully-gapped anisotropic ±s-wave superconductivity consistently explains experimental observations. In our phenomenological model, the gaps are assumed to be anisotropic on the electron-like β Fermi surfaces around the M point, where the maximum of the anisotropic gap is about four times larger than the minimum.

The charged surfaces of micaceous minerals, especially illite, regulate the mobility of the major radioisotopes of Cs (Cs, Cs,Cs) in the geosphere. Despite the long history of Cs adsorption studies, the nature of the illite surface sites remains incompletely understood. To address this problem, we present atomistic simulations of Cs competition with Na for three candidate illite adsorption sites - edge, basal plane, and interlayer. Our simulation results are broadly consistent with affinities and selectivities that have been inferred from surface complexation models. Cation exchange on the basal planes is thermodynamically ideal, but exchange on edge surfaces and within interlayers shows complex, thermodynamically non-ideal behavior. The basal planes are weakly Cs-selective, while edges and interlayers have much higher affinity for Cs. The dynamics of NaCs exchange are rapid for both cations on the basal planes, but considerably slower for Cs localized on edge surfaces. In addition to new insights into Cs adsorption and exchange with Na on illite, we report the development of a methodology capable of simulating fully-flexible clay mineral nanoparticles with stable edge surfaces using a well-tested interatomic potential model.

To explore whether a flat-band system can accommodate superconductivity, we consider repulsively interacting fermions on the diamond chain, a simplest quasi-one-dimensional system that contains a flat band. Exact diagonalization and the density-matrix renormalization group (DMRG) are used to show that we have a significant binding energy of a Cooper pair with a long-tailed pair-pair correlation in real space when the total band filling is slightly below 1/3, where a filled dispersive band interacts with the flat band that is empty but close to EF . Pairs selectively formed across the outer sites of the diamond chain are responsible for the pairing correlation. At exactly 1/3-filling an insulating phase emerges, where the entanglement spectrum indicates the particles on the outer sites are highly entangled and topological. These come from a peculiarity of the flat band in which "Wannier orbits" are not orthogonalizable.PACS numbers: 74.20. Rp, 71.10.Fd, 67.85.Lm Introduction-While fascinations with unconventional superconductivity arising from electron correlation continue to increase, as exemplified by the high-T C cuprates and iron-based superconductors, a next question to ask is whether there exists an avenue where we have superconductivity with another pairing mechanism. Namely, in the superconductivity in correlated electron systems, the standard viewpoint is that the interaction mediated by spin fluctuations glues the electrons into anisotropic pairs such as d-wave or s +− , where the nesting of the Fermi surface dominates the fluctuation, hence the superconductivity. To look for a different class of models, one intriguing direction is to consider correlated systems on flat-band lattices that contain dispersionless band(s) in their band structure. This is because, regardless of the Fermi energy residing on or off the flat band, we cannot define the Fermi surface for the flat band. In other words, we cannot apply, in one-dimensional cases, TomonagaLuttinger picture for the states around E F even with multichannel g-ology unlike the case of ladders. Thus, if superconductivity does arise, this might harbor a mechanism in which the flat band plays a role distinct from the conventional, nesting-dominated boson-exchange mechanisms.In the field of ferromagnetism, on the other hand, there is a long history for the study of flat-band ferromagnetism 1-3 , which is distinct from the conventional (Stoner) ferromagnetism.The ferromagnetic ground state is rigorously shown for arbitrary repulsive interaction 0 < U ≤ ∞ when the flat band is half-filled. The flat-band lattice models are conceived as Lieb model 1 with different numbers of A and B sublattice sites, or Mielke and Tasaki models 2,3 such as kagome lattice. A speciality of these flat-band lattices appears as an anomalous situation that Wannier orbitals cannot be orthogonalized, which is called the connectivity condition for the density matrix 4 . This immediately dictates that the flat band arises from interferences, hence totally different from the atomic (ze...

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Initial volumes of the parotid glands are significantly correlated with the grade of xerostomia in patients treated with IMRT. The volume of the parotid glands decreased significantly during the course of IMRT.

We propose a method to create a nontrivial Haldane phase in an atomic two-component Fermi gas loaded on a one-dimensional optical lattice with trap potential. The Haldane phase is naturally formed on a p-band Mott core in a wide range of the strong on-site repulsive interaction. The present proposal is composed of two steps, one of which is theoretical derivation of an effective 1D S=1 interacting-chain model from the original tight-binding Hamiltonian handling the two p orbitals, and the other of which is a numerical demonstration employing the density-matrix renormalization group for the formation of the Haldane phase on a p-band Mott core and its associated features in the original tight-binding model with the harmonic trap potential.

We examine quantum phases emerged by double degeneracy of p-orbital bands in attractive atomic Fermi gases loaded on a 1D optical lattice. Our numerical simulations by the density-matrix renormalization group predict the emergence of a state with a charge excitation gap, the Haldane insulator phase. A mapping onto an effective spin-1 model reveals its physical origin. Moreover, we show that population imbalance leads to richer diversity of the quantum phases, including a phase-separated polarized state. Finally, we study the effects of harmonic trap potential in this 1D chain.