8,413 research outputs found
The Tomonaga-Luttinger Model and the Chern-Simons Theory for the Edges of Multi-layer Fractional Quantum Hall Systems
Wen's chiral Tomonaga-Luttinger model for the edge of an m-layer quantum Hall
system of total filling factor nu=m/(pm +- 1) with even p, is derived as a
random-phase approximation of the Chern-Simons theory for these states. The
theory allows for a description of edges both in and out of equilibrium,
including their collective excitation spectrum and the tunneling exponent into
the edge. While the tunneling exponent is insensitive to the details of a
nu=m/(pm + 1) edge, it tends to decrease when a nu=m/(pm - 1) edge is taken out
of equilibrium. The applicability of the theory to fractional quantum Hall
states in a single layer is discussed.Comment: 15 page
Gauging Nonlinear Supersymmetry
Coset methods are used to construct the action describing the dynamics
associated with the spontaneous breaking of the local supersymmetries. The
resulting action is an invariant form of the Einstein-Hilbert action, which in
addition to the gravitational vierbein, also includes a massive gravitino
field. Invariant interactions with matter and gauge fields are also
constructed. The effective Lagrangian describing processes involving the
emission or absorption of a single light gravitino is analyzed.Comment: 20 pages, no figure
A minimal nonfinitely based semigroup whose variety is polynomially recognizable
We exhibit a 6-element semigroup that has no finite identity basis but
nevertheless generates a variety whose finite membership problem admits a
polynomial algorithm.Comment: 16 pages, 3 figure
Parafermions, parabosons and representations of so(\infty) and osp(1|\infty)
The goal of this paper is to give an explicit construction of the Fock spaces
of the parafermion and the paraboson algebra, for an infinite set of
generators. This is equivalent to constructing certain unitary irreducible
lowest weight representations of the (infinite rank) Lie algebra so(\infty) and
of the Lie superalgebra osp(1|\infty). A complete solution to the problem is
presented, in which the Fock spaces have basis vectors labelled by certain
infinite but stable Gelfand-Zetlin patterns, and the transformation of the
basis is given explicitly. We also present expressions for the character of the
Fock space representations
Total Polarisation Conversion in Two-dimensional Electron System under Cyclotron Resonance Conditions
The polarisation conversion of a linear polarised electromagnetic wave
incident onto a two-dimensional (2D) electron system at an angle is
theoretically studied. We consider the 2D system located at the interface
between two dielectric media with different dielectric constants. An external
dc magnetic field is assumed to be directed along the normal to the 2D electron
layer. In such a configuration the cyclotron-polaritons (CPs) in 2D electron
system can be excited with the frequencies in the vicinity of the cyclotron
frequency. Under the CPs excitation the resonance polarisation conversion of
electromagnetic wave greatly increases in the system. In the absence of the
electron scattering in 2D system, the polarisation conversion reaches 100% at a
certain value of the angle of incidence which is more than the total reflection
angle. Extremely high polarisation conversion takes place in a quite wide range
of variation of the angle of incidence. High polarisation conversion efficiency
(above 80%) remains when the actual electron scattering in the 2D system on
GsAs is taken into account. The considered phenomena may be taken up in
polarisation spectroscopy of 2D electron systems.Comment: 7 pages, 5 Postscript figure
Dynamics of Fluxon Lattice in Two Coupled Josephson Junctions
We study theoretically the dynamics of a fluxon Lattice (FL) in two coupled
Josephson junctions. We show that when the velocity of the moving FL exceeds
certain values , sharp resonances arise in the system which are
related to the excitation of the optical and acoustic collective modes. In the
interval a reconstruction of the FL occurs. We also establish that
one can excite localized nonlinear distortions (dislocations) which may
propagate through the FL and carry an arbitrary magnetic flux.Comment: 4 pages, 3 figures, corected typo
Carrier drift velocity and edge magnetoplasmons in graphene
We investigate electron dynamics at the graphene edge by studying the
propagation of collective edge magnetoplasmon (EMP) excitations. By timing the
travel of narrow wave-packets on picosecond time scales around exfoliated
samples, we find chiral propagation with low attenuation at a velocity which is
quantized on Hall plateaus. We extract the carrier drift contribution from the
EMP propagation and find it to be slightly less than the Fermi velocity, as
expected for an abrupt edge. We also extract the characteristic length for
Coulomb interaction at the edge and find it to be smaller than for soft,
depletion edge systems.Comment: 5 pages, 3 figures of main text and 6 pages, 6 figures of
supplemental materia
- …