Spin-twist driven persistent current in a strongly correlated two-dimensional electron system: a manifestation of the gauge field

A persistent current, coupled with the spin state, of purely many-body origin is shown to exist in Nagaoka's ferromagnetic state in two dimensions (2D). This we regard as a manifestation of a gauge field, which comes from the surrounding spin configuration and acts on the hole motion, being coupled to the Aharonov-Bohm flux. This provides an example where the electron-electron interaction exerts a profound effect involving the spins in clean two-dimensional lattice systems in sharp contrast to continuum or spinless fermion systems.Comment: 11 pages, typeset using Revtex 3.0, Phys. Rev. B in press, 2 figures available upon request at [email protected]

Persistent Current in the Ferromagnetic Kondo Lattice Model

In this paper, we study the zero temperature persistent current in a ferromagnetic Kondo lattice model in the strong coupling limit. In this model, there are spontaneous spin textures at some values of the external magnetic flux. These spin textures contribute a geometric flux, which can induce an additional spontaneous persistent current. Since this spin texture changes with the external magnetic flux, we find that there is an anomalous persistent current in some region of magnetic flux: near Phi/Phi_0=0 for an even number of electrons and Phi/Phi_0=1/2 for an odd number of electrons.Comment: 6 RevTeX pages, 10 figures include

Proposed Measurement of an Effective Flux Quantum in the Fractional Quantum Hall Effect

We consider a channel of an incompressible fractional-quantum-Hall-effect (FQHE) liquid containing an island of another FQHE liquid. It is predicted that the resistance of this channel will be periodic in the flux through the island, with the period equal to an odd integer multiple of the fundamental flux quantum, $\phi_{0}=hc/e$. The multiplicity depends on the quasiparticle charges of the two FQHE liquids.Comment: Late

Persistent current of two-chain Hubbard model with impurities

The interplay between impurities and interactions is studied in the gapless phase of two-chain Hubbard model in order to see how the screening of impurity potentials due to repulsive interactions in single-chain model will be changed by increasing the number of channels. Renormalization group calculations show that charge stiffness, and hence persistent current, of the two-chain model are less enhanced by interactions than single chain case.Comment: 4 Pages, RevTeX, No figures, Submitted to PR

Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective

This Report has a number of inter-related general purposes. One is to explore the extent to which food, nutrition, physical activity, and body composition modify the risk of cancer, and to specify which factors are most important. To the extent that environmental factors such as food, nutrition, and physical activity influence the risk of cancer, it is a preventable disease. The Report specifies recommendations based on solid evidence which, when followed, will be expected to reduce the incidence of cancer

Spin and interaction effects on charge distribution and currents in one-dimensional conductors and rings within the Hartree-Fock approximation

Using the self--consistent Hartree-Fock approximation for electrons with spin at zero temperature, we study the effect of the electronic interactions on the charge distribution in a one-dimensional continuous ring containing a single $\delta$ scatterer. We reestablish that the interaction suppresses the decay of the Friedel oscillations. Based on this result, we show that in an infinite one dimensional conductor containing a weak scatterer, the current is totally suppressed because of a gap opened at the Fermi energy. In a canonical ensemble of continuous rings containing many scatterers, the interactions enhance the average and the typical persistent current.Comment: 5 pages, 4 figure

Isotropic Transverse XY Chain with Energy- and Magnetization Currents

The ground-state correlations are investigated for an isotropic transverse XY chain which is constrained to carry either a current of magnetization J_M or a current of energy J_E. We find that the effect of nonzero J_M on the large-distance decay of correlations is twofold: i) oscillations are introduced and ii) the amplitude of the power law decay increases with increasing current. The effect of energy current is more complex. Generically, correlations in current carrying states are found to decay faster than in the J_E=0 states, contrary to expectations that correlations are increased by the presence of currents. However, increasing the current, one reaches a special line where the correlations become comparable to those of the J_E=0 states. On this line, the symmetry of the ground state is enhanced and the transverse magnetization vanishes. Further increase of the current destroys the extra symmetry but the transverse magnetization remains at the high-symmetry, zero value.Comment: 7 pages, RevTex, 4 PostScript figure

EXTRAPOLATION OF NUCLEAR WASTER GLASS AGING

Increased confidence is provided to the extrapolation of long-term waste form behavior by comparing the alteration of experimentally aged natural basaltic glass to the condition of the same glass as it has been geologically aged. The similarity between the laboratory and geologic alterations indicates that important aging variables have been identified and incorporated into the laboratory experiments. This provides credibility to the long-term predictions made for waste form borosilicate glasses using similar experimental procedures. In addition, these experiments have demonstrated that the aging processes for natural basaltic glass are relevant to the alteration of nuclear waste glasses, as both appear to react via similar processes. The alteration of a synthetic basaltic glass was measured in MCC-1 tests done at 90/sup 0/C, a SA/V of 0.1 cm/sup -1/ and time periods up to 182 days. Tests were also done using (1) MCC-2 procedures at 190/sup 0/C, a SA/V of 0.1 cm/sup -1/ and time periods up to 91 days and (2) hydration tests in saturated water vapor at 240/sup 0/C, a SA/V of approx. 10/sup 6/ cm/sup -1/, and time periods up to 63 days. These results are compared to alteration observed in natural basaltic glasses of great age. 6 references, 6 figures, 1 table

Chiral persistent currents and magnetic susceptibilities in the parafermion quantum Hall states in the second Landau level with Aharonov-Bohm flux

Using the effective conformal field theory for the quantum Hall edge states we propose a compact and convenient scheme for the computation of the periods, amplitudes and temperature behavior of the chiral persistent currents and the magnetic susceptibilities in the mesoscopic disk version of the Z_k parafermion quantum Hall states in the second Landau level. Our numerical calculations show that the persistent currents are periodic in the Aharonov-Bohm flux with period exactly one flux quantum and have a diamagnetic nature. In the high-temperature regime their amplitudes decay exponentially with increasing the temperature and the corresponding exponents are universal characteristics of non-Fermi liquids. Our theoretical results for these exponents are in perfect agreement with those extracted from the numerical data and demonstrate that there is in general a non-trivial contribution coming from the neutral sector. We emphasize the crucial role of the non-holomorphic factors, first proposed by Cappelli and Zemba in the context of the conformal field theory partition functions for the quantum Hall states, which ensure the invariance of the annulus partition function under the Laughlin spectral flow.Comment: 14 pages, RevTeX4, 7 figures (eps