155 research outputs found

    Exact Multiplicities in the Three-Anyon Spectrum

    Full text link
    Using the symmetry properties of the three-anyon spectrum, we obtain exactly the multiplicities of states with given energy and angular momentum. The results are shown to be in agreement with the proper quantum mechanical and semiclassical considerations, and the unexplained points are indicated.Comment: 16 pages plus 3 postscript figures, Kiev Institute for Theoretical Physics preprint ITP-93-32

    Novel FixL homologues in Chlamydomonas reinhardtii bind heme and O2

    Get PDF
    AbstractGenome inspection revealed nine putative heme-binding, FixL-homologous proteins in Chlamydomonas reinhardtii. The heme-binding domains from two of these proteins, FXL1 and FXL5 were cloned, expressed in Escherichia coli, purified and characterized. The recombinant FXL1 and FXL5 domains stained positively for heme, while mutations in the putative ligand-binding histidine FXL1-H200S and FXL5-H200S resulted in loss of heme binding. The FXL1 and FXL5 [Fe(II), bound O2] had Soret absorption maxima around 415nm, and weaker absorptions at longer wavelengths, in concurrence with the literature. Ligand-binding measurements showed that FXL1 and FXL5 bind O2 with moderate affinity, 135 and 222ÎŒM, respectively. This suggests that Chlamydomonas may use the FXL proteins in O2-sensing mechanisms analogous to that reported in nitrogen-fixing bacteria to regulate gene expression

    Time-reversal violating rotation of polarization plane of light in gas placed in electric field

    Get PDF
    Rotation of polarization plane of light in gas placed in electric field is considered. Different factors causing this phenomenon are investigated. Angle of polarization plane rotation for transition 6S_{1/2} - 7S_{1/2} in cesium (lambda=539 nm) is estimated. The possibility to observe this effect experimentally is discussed.Comment: 10 pages, Late

    On unquenched N=2 holographic flavor

    Get PDF
    The addition of fundamental degrees of freedom to a theory which is dual (at low energies) to N=2 SYM in 1+3 dimensions is studied. The gauge theory lives on a stack of Nc D5 branes wrapping an S^2 with the appropriate twist, while the fundamental hypermultiplets are introduced by adding a different set of Nf D5-branes. In a simple case, a system of first order equations taking into account the backreaction of the flavor branes is derived (Nf/Nc is kept of order 1). From it, the modification of the holomorphic coupling is computed explicitly. Mesonic excitations are also discussed.Comment: 25 pages, 4 figure

    Quantum Mechanics and Thermodynamics of Particles with Distance Dependent Statistics

    Full text link
    The general notion of distance dependent statistics in anyon-like systems is discussed. The two-body problem for such statistics is considered, the general formula for the second virial coefficient is derived and it is shown that in the limiting cases it reproduces the known results for ideal anyons.Comment: 9 pages, LATEX Kiev Institute for Theoretical Physics preprint ITP-93-5E, January 199

    Limits on the monopole magnetic field from measurements of the electric dipole moments of atoms, molecules and the neutron

    Full text link
    A radial magnetic field can induce a time invariance violating electric dipole moment (EDM) in quantum systems. The EDMs of the Tl, Cs, Xe and Hg atoms and the neutron that are produced by such a field are estimated. The contributions of such a field to the constants, χ\chi of the T,P-odd interactions χeN⋅s/s\chi_e {\bf N} \cdot {\bf s}/s and χNN⋅I/I\chi_N {\bf N} \cdot {\bf I}/I are also estimated for the TlF, HgF and YbF molecules (where s{\bf s} (I{\bf I}) is the electron (nuclear) spin and N{\bf N} is the molecular axis). The best limit on the contact monopole field can be obtained from the measured value of the Tl EDM. The possibility of such a field being produced from polarization of the vacuum of electrically charged magnetic monopoles (dyons) by a Coulomb field is discussed, as well as the limit on these dyons. An alternative mechanism involves chromomagnetic and chromoelectric fields in QCD.Comment: Uses RevTex, 16 pages, 4 postscript figures. An explanation of why there is no orbital contribution to the EDM has been added, and the presentation has been improved in genera

    Fundamental matter, meson spectroscopy and non-critical string/gauge duality

    Full text link
    We discuss the incorporation of quarks in the fundamental representation of the color group into the non-critical string/gauge duality. We focus on confining theories and address this question using two different approaches: (i) by introducing flavor probe branes and (ii) by deriving backreacted flavored near extremal gravity backgrounds. In the former approach we analyze the near extremal AdS_6 model with D4 and anti-D4 probe flavor branes included. We study the meson spectrum and discuss the role played by the constituent quark mass, related to the integration constant that defines the embedding. As for the second approach we derive a class of flavored AdS_{n+1} x S^k black hole solutions. In particular we write down the flavored AdS_6 and AdS_5 black holes and the near extremal AdS_5 x S^1 backgrounds. We analyze several gauge dynamical properties associated with these models.Comment: 46 pages, 7 figures. v.2: some references and a comment about the comparison with analogous critical models were added. v.3: a comment added; published versio

    Fermion Chern Simons Theory of Hierarchical Fractional Quantum Hall States

    Full text link
    We present an effective Chern-Simons theory for the bulk fully polarized fractional quantum Hall (FQH) hierarchical states constructed as daughters of general states of the Jain series, {\it i. e.} as FQH states of the quasi-particles or quasi-holes of Jain states. We discuss the stability of these new states and present two reasonable stability criteria. We discuss the theory of their edge states which follows naturally from this bulk theory. We construct the operators that create elementary excitations, and discuss the scaling behavior of the tunneling conductance in different situations. Under the assumption that the edge states of these fully polarized hierarchical states are unreconstructed and unresolved, we find that the differential conductance GG for tunneling of electrons from a Fermi liquid into {\em any} hierarchical Jain FQH states has the scaling behavior G∌VαG\sim V^\alpha with the universal exponent α=1/Îœ\alpha=1/\nu, where Îœ\nu is the filling fraction of the hierarchical state. Finally, we explore alternative ways of constructing FQH states with the same filling fractions as partially polarized states, and conclude that this is not possible within our approach.Comment: 10 pages, 50 references, no figures; formerly known as "Composite Fermions: The Next Generation(s)" (title changed by the PRB thought police). This version has more references and a discussion of the stability of the new states. Published version. One erroneous reference is correcte

    Competition between quantum-liquid and electron-solid phases in intermediate Landau levels

    Full text link
    On the basis of energy calculations we investigate the competition between quantum-liquid and electron-solid phases in the Landau levels n=1,2, and 3 as a function of their partial filling factor. Whereas the quantum-liquid phases are stable only in the vicinity of quantized values 1/(2s+1) of the partial filling factor, an electron solid in the form of a triangular lattice of clusters with a few number of electrons (bubble phase) is energetically favorable between these fillings. This alternation of electron-solid phases, which are insulating because they are pinned by the residual impurities in the sample, and quantum liquids displaying the fractional quantum Hall effect explains a recently observed reentrance of the integral quantum Hall effect in the Landau levels n=1 and 2. Around half-filling of the last Landau level, a uni-directional charge density wave (stripe phase) has a lower energy than the bubble phase.Comment: 12 pages, 9 figures; calculation of exact exchange potential for n=1,2,3 included, energies of electron-solid phases now calculated with the help of the exact potential, and discussion of approximation include

    Fluctuation-dissipation relations in the non-equilibrium critical dynamics of Ising models

    Full text link
    We investigate the relation between two-time, multi-spin, correlation and response functions in the non-equilibrium critical dynamics of Ising models in d=1 and d=2 spatial dimensions. In these non-equilibrium situations, the fluctuation-dissipation theorem (FDT) is not satisfied. We find FDT `violations' qualitatively similar to those reported in various glassy materials, but quantitatively dependent on the chosen observable, in contrast to the results obtained in infinite-range glass models. Nevertheless, all FDT violations can be understood by considering separately the contributions from large wavevectors, which are at quasi-equilibrium and obey FDT, and from small wavevectors where a generalized FDT holds with a non-trivial limit fluctuation-dissipation ratio X. In d=1, we get X = 1/2 for spin observables, which measure the orientation of domains, while X = 0 for observables that are sensitive to the domain-wall motion. Numerical simulations in d=2 reveal a unique X = 0.34 for all observables. Measurement protocols for X are discussed in detail. Our results suggest that the definition of an effective temperature Teff = T / X for large length scales is generically possible in non-equilibrium critical dynamics.Comment: 26 pages, 10 figure
    • 

    corecore