Addendum to ``Multichannel Kondo screening in a one-dimensional correlated electron system''

This is an addendum to our previous work cond-mat/9705048 (published in Europhysics Letters 41, 213 (1998)), clarifying the construction of the two-particle scattering matrices used for studying the magnetic impurity behavior in a multichannel correlated host.Comment: Addendum to cond-mat/9705048 (Europhys. Lett. 41, 213 (1998)

Multichannel Kondo Screening in a One-Dimensional Correlated Electron System

We present the exact Bethe Ansatz solution of a multichannel model of one- dimensional correlated electrons coupled antiferromagnetically to a magnetic impurity of arbitrary spin S. The solution reveals that interactions in the bulk make the magnetic impurity drive both spin and charge fluctuations, producing a mixed valence at the impurity site, with an associated effective spin S_eff > S in the presence of a magnetic field. The screening of the impurity spin is controlled by its size independently of the number of channels, in contrast to the multichannel Kondo effect for free electrons.Comment: 5 pages Revtex. Final revised version to appear in Europhys. Let

Advection Dominated Accretion Flows Around Kerr Black Holes

We derive all relevant equations needed for constructing a global general relativistic model of advectively cooled, very hot, optically thin accretion disks around black holes and present solutions which describe advection dominated flows in the gravitational field of a Kerr black hole.Comment: ApJ submitte

SURVEY OF UPPER RATTLESNAKE CREEK, A TROUT-SPAWNING TRIBUTARY OF THE CLARK FORK RIVER (MT), FOR TUBIFEX TUBIFEX

Rattlesnake Creek is a tributary of the Clark Fork River that flows through parts of western Montana and through Missoula. Currently, an effort is underway to increase spawning habitat for bull and westslope cutthroat trout in the Clark Fork drainage. One proposal in this effort includes the modification or removal of the Mountain Water Company dam on lower Rattlesnake Creek that currently blocks fish passage. The removal or modification of this dam would open miles of prime spawning habitat. However, the Clark Fork River is known to be contaminated with Myxobolus cerebralis, the causative agent of salmonid whirling disease. The presence of this parasite in the Clark Fork River has lead to concerns that removal/modification of the dam would allow the parasite to spread into the upper reaches of Rattlesnake Creek, endangering the wild trout populations already established there. Therefore, the objective of this study was to survey the upper portions of Rattlesnake Creek for the presence of the aquatic oligochaete, Tubifex tubifex. T. tubifex is an obligatory host for M. cerebralis and the parasite cannot be transmitted to trout in its absence. An earlier, cursory study by another investigator did not detect T. tubifex in the Rattlesnake, so we conducted a more comprehensive survey of the creek for this oligochaete. Further, these worms were screened for the presence of M. cerebralis triactinomyxons (TAMs; stage of parasite that infects trout)

Mitigating wildfire carbon loss in managed northern peatlands through restoration

Northern peatlands can emit large amounts of carbon and harmful smoke pollution during a wildfire. Of particular concern are drained and mined peatlands, where management practices destabilize an array of ecohydrological feedbacks, moss traits and peat properties that moderate water and carbon losses in natural peatlands. Our results demonstrate that drained and mined peatlands in Canada and northern Europe can experience catastrophic deep burns (>200 t C ha(-1) emitted) under current weather conditions. Furthermore, climate change will cause greater water losses in these peatlands and subject even deeper peat layers to wildfire combustion. However, the rewetting of drained peatlands and the restoration of mined peatlands can effectively lower the risk of these deep burns, especially if a new peat moss layer successfully establishes and raises peat moisture content. We argue that restoration efforts are a necessary measure to mitigate the risk of carbon loss in managed peatlands under climate change

The Dynamical Mean Field Theory phase space extension and critical properties of the finite temperature Mott transition

We consider the finite temperature metal-insulator transition in the half filled paramagnetic Hubbard model on the infinite dimensional Bethe lattice. A new method for calculating the Dynamical Mean Field Theory fixpoint surface in the phase diagram is presented and shown to be free from the convergence problems of standard forward recursion. The fixpoint equation is then analyzed using dynamical systems methods. On the fixpoint surface the eigenspectra of its Jacobian is used to characterize the hysteresis boundaries of the first order transition line and its second order critical end point. The critical point is shown to be a cusp catastrophe in the parameter space, opening a pitchfork bifurcation along the first order transition line, while the hysteresis boundaries are shown to be saddle-node bifurcations of two merging fixpoints. Using Landau theory the properties of the critical end point is determined and related to the critical eigenmode of the Jacobian. Our findings provide new insights into basic properties of this intensively studied transition.Comment: 11 pages, 12 figures, 1 tabl

Distributional exact diagonalization formalism for quantum impurity models

We develop a method for calculating the self-energy of a quantum impurity coupled to a continuous bath by stochastically generating a distribution of finite Anderson models that are solved by exact diagonalization, using the noninteracting local spectral function as a probability distribution for the sampling. The method enables calculation of the full analytic self-energy and single-particle Green's function in the complex frequency plane, without analytic continuation, and can be used for both finite and zero temperature at arbitrary fillings. Results are in good agreement with imaginary frequency data from continuous-time quantum Monte Carlo calculations for the single impurity Anderson model and the two-orbital Hubbard model within dynamical mean field theory (DMFT) as well as real frequency data for self energy of the single band Hubbard model within DMFT using numerical renormalization group. The method should be applicable to a wide range of quantum impurity models and particularly useful when high-precision real frequency results are sought.Comment: Two band calculation updated, 4 pages, 4 figure

Kondo effect in crossed Luttinger liquids

We study the Kondo effect in two crossed Luttinger liquids, using Boundary Conformal Field Theory. We predict two types of critical behaviors: either a two-channel Kondo fixed point with a nonuniversal Wilson ratio, or a new theory with an anomalous response identical to that found by Furusaki and Nagaosa (for the Kondo effect in a single Luttinger liquid). Moreover, we discuss the relevance of perturbations like channel anisotropy, and we make links with the Kondo effect in a two-band Hubbard system modeled by a channel-dependent Luttinger Hamiltonian. The suppression of backscattering off the impurity produces a model similar to the four-channel Kondo theory.Comment: 7 pages, RevteX, to be published in Physical Review

One-Dimensional Electron Liquid in an Antiferromagnetic Environment: Spin Gap from Magnetic Correlations

We study a one-dimensional electron liquid coupled by a weak spin-exchange interaction to an antiferromagnetic spin-S ladder with n legs. A perturbative renormalization group analysis in the semiclassical limit reveals the opening of a spin gap, driven by the local magnetic correlations on the ladder. The effect, which we argue is present for any gapful ladder or gapless ladder with $nS\gg 1$, is enhanced by the repulsive interaction among the conduction electrons but is insensitive to the sign of the spin exchange interaction with the ladder. Possible implications for the striped phases of the cuprates are discussed.Comment: 5 pages, 1 figure, to appear in Phys. Rev. Let