Magnetic-field-induced Luttinger liquid

It is shown that a strong magnetic field applied to a bulk metal induces a Luttinger-liquid phase. This phase is characterized by the zero-bias anomaly in tunneling: the tunneling conductance scales as a power-law of voltage or temperature. The tunneling exponent increases with the magnetic field as BlnB. The zero-bias anomaly is most pronounced for tunneling with the field applied perpendicular to the plane of the tunneling junction.Comment: a reference added, minor typos correcte

Nucleation of superconducting pairing states at mesoscopic scales at zero temperature

We find the spin polarized disordered Fermi liquids are unstable to the nucleation of superconducting pairing states at mesoscopic scales even when magnetic fields which polarize the spins are substantially higher than the critical one. We study the probability of finding superconducting pairing states at mesoscopic scales in this limit. We find that the distribution function depends only on the film conductance. The typical length scale at which pairing takes place is universal, and decreases when the magnetic field is increased. The number density of these states determines the strength of the random exchange interactions between mesoscopic pairing states.Comment: 11 pages, no figure

Tunneling of correlated electrons in ultra high magnetic field

Effects of the electron-electron interaction on tunneling into a metal in ultra-high magnetic field (ultra-quantum limit) are studied. The range of the interaction is found to have a decisive effect both on the nature of the field-induced instability of the ground state and on the properties of the system at energies above the corresponding gap. For a short-range repulsive interaction, tunneling is dominated by the renormalization of the coupling constant, which leads eventually to the charge-density wave instability. For a long-range interaction, there exists an intermediate energy range in which the conductance obeys a power-law scaling form, similar to that of a 1D Luttinger liquid. The exponent is magnetic-field dependent, and more surprisingly, may be positive or negative, i. e., interactions may either suppress or enhance the tunneling conductance compared to its non-interacting value. At energies near the gap, scaling breaks down and tunneling is again dominated by the instability, which in this case is an (anisotropic) Wigner crystal instability.Comment: 4 pages, 2 .eps figure

Generalized Fock spaces and the Stirling numbers

The Bargmann-Fock-Segal space plays an important role in mathematical physics, and has been extended into a number of directions. In the present paper we imbed this space into a Gelfand triple. The spaces forming the Fr\'echet part (i.e. the space of test functions) of the triple are characterized both in a geometric way and in terms of the adjoint of multiplication by the complex variable, using the Stirling numbers of the second kind. The dual of the space of test functions has a topological algebra structure, of the kind introduced and studied by the first named author and G. Salomon.Comment: revised versio

Neuroplasticity in cholinergic projections from basal forebrain to the basolateral nucleus of amygdala in the kainic acid model of temporal lobe epilepsy

The amygdala is a cerebral region whose function is compromised in temporal lobe epilepsy (TLE). Patients with TLE present cognitive and emotional dysfunctions, of which impairments in recognizing facial expressions have been clearly attributed to amygdala damage. However, damage to the amygdala has been scarcely addressed, with the majority of studies focusing on the hippocampus. The aim of this study was to evaluate epilepsy-related plasticity of cholinergic projections to the basolateral nucleus (BL) of the amygdala. Adult rats received kainic acid (KA) injections and developed status epilepticus. Weeks later, they showed spontaneous recurrent seizures documented by behavioral observations. Changes in cholinergic innervation of the BL were investigated by using an antibody against the vesicular acetylcholine transporter (VAChT). In KA-treated rats, it was found that (i) the BL shrunk to 25% of its original size (p < 0.01 vs. controls, Student’s t-test), (ii) the density of vesicular acetylcholine transporter-immunoreactive (VAChT-IR) varicosities was unchanged, (iii) the volumes of VAChT-IR cell bodies projecting to the BL from the horizontal limb of the diagonal band of Broca, ventral pallidum, and subcommissural part of the substantia innominata were significantly increased (p < 0.05, Bonferroni correction). These results illustrate significant changes in the basal forebrain cholinergic cells projecting to the BL in the presence of spontaneous recurrent seizures

Many-Body Effects on Tunneling of Electrons in Magnetic-Field-Induced Quasi One-Dimensional Electron Systems in Semiconductor Nanowhiskers

Effects of the electron-electron interaction on tunneling in a semiconductor nanowhisker are studied in a magnetic quantum limit. We consider the system with which bulk and edge states coexist. In bulk states, the temperature dependence of the transmission probability is qualitatively similar to that of a one-dimensional electron system. We investigate contributions of edge states on transmission probability in bulk states. Those contributions can be neglected within our approximation which takes into account only most divergent terms at low temperatures.Comment: 9 pages, 6 figure

Modification of the standard model for the lanthanides

We show that incorporation of strong electron correlations into the Kohn-Sham scheme of band structure calculations leads to a modification of the standard model of the lanthanides and that this procedure removes the existing discrepancy between theory and experiment concerning the ground state properties. Within the picture suggested, part of the upper Hubbard $f$-band is occupied due to conduction band-$f$-mixing interaction (that is renormalized due to correlations) and this contributes to the cohesive energy of the crystal. The lower Hubbard band has zero width and describes fermionic excitations in the shell of localized $f$-s. Fully self-consistent calculations (with respect to both charge density and many-electron population numbers of the $f$-shell) of the equilibrium volume $V_0$ and the bulk modulus of selected lanthanides have been performed and a good agreement is obtained.Comment: 1 fi

Unconventional magnetoresistance in long InSb nanowires

Magnetoresistance in long correlated nanowires of degenerate semiconductor InSb in asbestos matrix (wire diameter of around 5 nm, length 0.1 - 1 mm) is studied over temperature range 2.3 - 300 K. At zero magnetic field the electric conduction $G$ and the current-voltage characteristics of such wires obey the power laws $G\propto T^\alpha$, $I\propto V^\beta$, expected for one-dimensional electron systems. The effect of magnetic field corresponds to a 20% growth of the exponents $\alpha$, $\beta$ at H=10 T. The observed magnetoresistance is caused by the magnetic-field-induced breaking of the spin-charge separation and represents a novel mechanism of magnetoresistance.Comment: To be published in JETP Letters, vol. 77 (2003