340 research outputs found
Formation of an Edge Striped Phase in Fractional Quantum Hall Systems
We have performed an exact diagonalization study of up to N=12 interacting
electrons on a disk at filling for both Coulomb and
short-range interaction for which Laughlin wave function is the exact solution.
For Coulomb interaction and we find persistent radial oscillations
in electron density, which are not captured by the Laughlin wave function. Our
results srongly suggest formation of a chiral edge striped phase in quantum
Hall systems. The amplitude of the charge density oscillations decays slowly,
perhaps as a square root of the distance from the edge; thus the spectrum of
edge excitations is likely to be affected.Comment: 4 pages, 3 Figs. include
On the solutions of the Schrodinger equation with some molecular potentials: wave function ansatz
Making an ansatz to the wave function, the exact solutions of the %
-dimensional radial Schrodinger equation with some molecular potentials like
pseudoharmonic and modified Kratzer potentials are obtained. The restriction on
the parameters of the given potential, and are also given,
where depends on a linear combination of the angular momentum quantum
number and the spatial dimensions and is a parameter in
the ansatz to the wave function. On inserting D=3, we find that the bound state
eigensolutions recover their standard analytical forms in literature.Comment: 14 page
Invariance of Charge of Laughlin Quasiparticles
A Quantum Antidot electrometer has been used in the first direct observation
of the fractionally quantized electric charge. In this paper we report
experiments performed on the integer i = 1, 2 and fractional f = 1/3 quantum
Hall plateaus extending over a filling factor range of at least 27%. We find
the charge of the Laughlin quasiparticles to be invariantly e/3, with standard
deviation of 1.2% and absolute accuracy of 4%, independent of filling,
tunneling current, and temperature.Comment: 4 pages, 5 fig
Reply to ``Comment on `Magnetic field effects on neutron diffraction in the antiferromagnetic phase of '''
Fak, van Dijk and Wills (FDW) question our interpretation of elastic
neutron-scattering experiments in the antiferromagnetic phase of UPt_3. They
state that our analysis is incorrect because we average over magnetic
structures that are disallowed by symmetry. We disagree with FDW and reply to
their criticism. FDW also point out that we have mistaken the magnetic field
direction in the experiment reported by N. H. van Dijk et al. [Phys. Rev. B 58,
3186 (1998)]. We correct this error and note that our previous conclusion is
also valid for the correct field orientation.Comment: 3 page
Hamiltonian Theory of the Composite Fermion Wigner Crystal
Experimental results indicating the existence of the high magnetic field
Wigner Crystal have been available for a number of years. While variational
wavefunctions have demonstrated the instability of the Laughlin liquid to a
Wigner Crystal at sufficiently small filling, calculations of the excitation
gaps have been hampered by the strong correlations. Recently a new Hamiltonian
formulation of the fractional quantum Hall problem has been developed. In this
work we extend the Hamiltonian approach to include states of nonuniform
density, and use it to compute the excitation gaps of the Wigner Crystal
states. We find that the Wigner Crystal states near are
quantitatively well described as crystals of Composite Fermions with four
vortices attached. Predictions for gaps and the shear modulus of the crystal
are presented, and found to be in reasonable agreement with experiments.Comment: 41 page, 6 figures, 3 table
T-Odd Correlations in pi->e nu_e gamma and pi->mu nu_mu gamma Decays
The transverse lepton polarization asymmetry in pi_l2gamma decays may probe
T-violating interactions beyond the Standard Model. Dalitz plot distributions
of the expected effects are presented and compared to the contribution from the
Standard Model final state interactions. We give an example of a
phenomenologically viable model, where a considerable contribution to the
transverse lepton polarization asymmetry arises.Comment: 19 pages, 5 figures. To be published in Phys.Rev.D. Fixed sign in FSI
contribution figure, fixed formulas in K-bar{K} mixing analysis, added some
minor comment
Time consistent discounting
A possibly immortal agent tries to maximise its summed discounted rewards over time, where discounting is used to avoid infinite utilities and encourage the agent to value current rewards more than future ones. Some commonly used discount functions lead to time-inconsistent behavior where the agent changes its plan over time. These inconsistencies can lead to very poor behavior. We generalise the usual discounted utility model to one where the discount function changes with the age of the agent. We then give a simple characterisation of time-(in)consistent discount functions and show the existence of a rational policy for an agent that knows its discount function is time-inconsistent
A General Approach for the Exact Solution of the Schrodinger Equation
The Schr\"{o}dinger equation is solved exactly for some well known
potentials. Solutions are obtained reducing the Schr\"{o}dinger equation into a
second order differential equation by using an appropriate coordinate
transformation. The Nikiforov-Uvarov method is used in the calculations to get
energy eigenvalues and the corresponding wave functions.Comment: 20 page
Tritium Beta Decay, Neutrino Mass Matrices and Interactions Beyond the Standard Model
The interference of charge-changing interactions, weaker than the V-A
Standard Model (SM) interaction and having a different Lorentz structure, with
that SM interaction, can, in principle, produce effects near the end point of
the Tritium beta decay spectrum which are of a different character from those
produced by the purely kinematic effect of neutrino mass expected in the
simplest extension of the SM. We show that the existence of more than one mass
eigenstate can lead to interference effects at the end point that are stronger
than those occurring over the entire spectrum. We discuss these effects both
for the special case of Dirac neutrinos and the more general case of Majorana
neutrinos and show that, for the present precision of the experiments, one
formula should suffice to express the interference effects in all cases.
Implications for "sterile" neutrinos are noted.Comment: 32 pages, LaTeX, 6 figures, PostScript; full discussion and changes
in notation from Phys. Lett. B440 (1998) 89, nucl-th/9807057; submitted to
Phys. Rev.
Early Life Characteristics and Neurodevelopmental Phenotypes in the Mount Sinai Children’s Environmental Health Center
Neurodevelopmental outcomes including behavior, executive functioning, and IQ exhibit complex correlational structures, although they are often treated as independent in etiologic studies. We performed a principal components analysis of the behavioral assessment system for children, the behavior rating inventory of executive functioning, and the Wechsler scales of intelligence in a prospective birth cohort, and estimated associations with early life characteristics. We identified seven factors: (1) impulsivity and externalizing, (2) executive functioning, (3) internalizing, (4) perceptual reasoning, (5) adaptability, (6) processing speed, and (7) verbal intelligence. Prenatal fish consumption, maternal education, preterm birth, and the home environment were important predictors of various neurodevelopmental factors. Although maternal smoking was associated with more adverse externalizing, executive functioning, and adaptive composite scores in our sample, of the orthogonally-rotated factors, smoking was only associated with the impulsivity and externalizing factor (β^ − 0.82, 95% CI − 1.42, − 0.23). These differences may be due to correlations among outcomes that were accounted for by using a phenotypic approach. Dimension reduction may improve upon traditional approaches by accounting for correlations among neurodevelopmental traits
- …