3,011 research outputs found
Note on the Electron Energy Spectrum in the Inner Van Allen Belt
Electron energy spectrum in the inner van allen bel
Geomagnetically Trapped Radiation Produced by a High-Altitude Nuclear Explosion on July 9, 1962
Geomagnetically trapped radiation produced by a high altitude nuclear explosio
Hierarchy wave functions--from conformal correlators to Tao-Thouless states
Laughlin's wave functions, describing the fractional quantum Hall effect at
filling factors , can be obtained as correlation functions in
conformal field theory, and recently this construction was extended to Jain's
composite fermion wave functions at filling factors . Here we
generalize this latter construction and present ground state wave functions for
all quantum Hall hierarchy states that are obtained by successive condensation
of quasielectrons (as opposed to quasiholes) in the original hierarchy
construction. By considering these wave functions on a cylinder, we show that
they approach the exact ground states, the Tao-Thouless states, when the
cylinder becomes thin. We also present wave functions for the multi-hole
states, make the connection to Wen's general classification of abelian quantum
Hall fluids, and discuss whether the fractional statistics of the
quasiparticles can be analytically determined. Finally we discuss to what
extent our wave functions can be described in the language of composite
fermions.Comment: 9 page
Pairing via Index theorem
This work is motivated by a specific point of view: at short distances and
high energies the undoped and underdoped cuprates resemble the -flux phase
of the t-J model. The purpose of this paper is to present a mechanism by which
pairing grows out of the doped -flux phase. According to this mechanism
pairing symmetry is determined by a parameter controlling the quantum tunneling
of gauge flux quanta. For zero tunneling the symmetry is ,
while for large tunneling it is . A zero-temperature critical
point separates these two limits
Experimental determination of dipole moments for molecular ions: Improved measurements for ArH^+
An improved value for the dipole moment of ArH^+ has been obtained from new measurements of the rotational g factors of ArH^+ and ArD^+ made with tunable far‐IR laser spectroscopy. Systematic errors present in earlier measurements have been eliminated. The new result (μ=3.0±0.6 D) is slightly higher than the ab initio value of Rosmus (2.2 D) at the 2σ limits of precision
Fractional Quantum Hall Effect and vortex lattices
It is demonstrated that all observed fractions at moderate Landau level
fillings for the quantum Hall effect can be obtained without recourse to the
phenomenological concept of composite fermions. The possibility to have the
special topologically nontrivial many-electron wave functions is considered.
Their group classification indicates the special values of of electron density
in the ground states separated by a gap from excited states
A First-Landau-Level Laughlin/Jain Wave Function for the Fractional Quantum Hall Effect
We show that the introduction of a more general closed-shell operator allows
one to extend Laughlin's wave function to account for the richer hierarchies
(1/3, 2/5, 3/7 ...; 1/5, 2/9, 3/13, ..., etc.) found experimentally. The
construction identifies the special hierarchy states with condensates of
correlated electron clusters. This clustering implies a single-particle (ls)j
algebra within the first Landau level (LL) identical to that of multiply filled
LLs in the integer quantum Hall effect. The end result is a simple generalized
wave function that reproduces the results of both Laughlin and Jain, without
reference to higher LLs or projection.Comment: Revtex. In this replacement we show how to generate the Jain wave
function explicitly, by acting with the generalized ls closed-shell operator
discussed in the original version. We also walk the reader through a
classical 1d caricature of this problem so that he/she can better understand
why 2s+1, where s is the spin, should be associated with the number of
electrons associated with the underlying clusters or composites. 11 page
Meron excitations in the nu =1 quantum Hall bilayer and the plasma analogy
We study meron quasiparticle excitations in the \nu = 1 quantum Hall bilayer.
Considering the well known single meron state, we introduce its effective form,
valid in the longdistance limit. That enables us to propose two (and more)
meron states in the same limit. Further, establishing a plasma analogy of the
(111) ground state, we find the impurities that play the role of merons and
derive meron charge distributions. Using the introduced meron constructions in
generalized (mixed) ground states and corresponding plasmas for arbitrary
distance between the layers, we calculate the interaction between the
construction implied impurities. We also find a correspondence between the
impurity interactions and meron interactions. This suggests a possible
explanation of the deconfinement of the merons recently observed in the
experiments.Comment: 5 pages, 3 figure
Spin Susceptibility and Gap Structure of the Fractional-Statistics Gas
This paper establishes and tests procedures which can determine the electron
energy gap of the high-temperature superconductors using the model
with spinon and holon quasiparticles obeying fractional statistics. A simpler
problem with similar physics, the spin susceptibility spectrum of the spin 1/2
fractional-statistics gas, is studied. Interactions with the density
oscillations of the system substantially decrease the spin gap to a value of
, much less than the mean-field value of
. The lower few Landau levels remain visible, though broadened
and shifted, in the spin susceptibility. As a check of the methods, the
single-particle Green's function of the non-interacting Bose gas viewed in the
fermionic representation, as computed by the same approximation scheme, agrees
well with the exact results. The same mechanism would reduce the gap of the
model without eliminating it.Comment: 35 pages, written in REVTeX, 16 figures available upon request from
[email protected]
Band Structure of the Fractional Quantum Hall Effect
The eigenstates of interacting electrons in the fractional quantum Hall phase
typically form fairly well defined bands in the energy space. We show that the
composite fermion theory gives insight into the origin of these bands and
provides an accurate and complete microscopic description of the strongly
correlated many-body states in the low-energy bands. Thus, somewhat like in
Landau's fermi liquid theory, there is a one-to-one correspondence between the
low energy Hilbert space of strongly interacting electrons in the fractinal
quantum Hall regime and that of weakly interacting electrons in the integer
quantum Hall regime.Comment: 10 page
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