1,989 research outputs found

    Cyclotron Resonance of Composite Fermions: Quantum Hall Effect

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    We have examined the claim made by Kukushkin et al that they have observed the cyclotron resonance of composite fermions. We find that the claim made is false and there is no justification for making false reports. The microwave absorption in cyclotron levels is observed and it is claimed that CF has been seen. Since "even flux quanta attachment to one electron" has not been seen, we find that Kukushkin's claim to have seen the CF is false. Since attachment of flux quanta to electrons can be an important discovery, Kukushkin et al have made the claim of seeing the CF without actually identifying them. The data can be interpreted without attaching flux quanta to the electrons.Comment: 5 pages Te

    Comments on``Theoretical search for the nested quantum Hall effect of composite fermions" by Mandal and Jain,Phys.Rev.B 66,155302(2002); cond-mat/0210181

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    We find that a large number of parameters are used to create the correct fractions. The parameters used are, \nu, 1-\nu,\nu^*,\bar n, n, p and \bar p. Therefore, the predicted fractions need not be having the correct origin. The wave function describes a composite fermion which has the 2p (even number) of flux quanta attached to one electron. We find that it requires ``decomposite fermion", which is the electron in an orbit from which the magnetic field has been detached. This kind of detachment (attachment) of flux quanta from (to) the electron is not consistent with the electromagnetic theory of light and violates Biot and Savart's law as well as theory of relativity. If flux quanta are to be attached to the electron, we should solve the bound-state equation and determine the binding energy but bound-state has not been solved. The wave function given is not a solution of the bound-state equation. Therefore,Mandal and Jain's composite fermion (CF) model is incorrect. electron, to the electron, we should solve the bound-state equation and determineComment: 7 pages TeX, 2 jpg figure

    Comments on "Anomalous-Filling-Factor-Dependent Nuclear Spin Polarization in a 2D Electron System: Quantum Hall Effect" by J.H.Smet, K. von Klitzing et al, Phys. Rev. Lett. 92, 086802(2004)

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    We find that the nuclear-spin polarization has not been treated correctly. The references given are those of wrong papers. The credits assigned for discoveries are also not correct. Incorrect theories have been cited. The reference to the correct theory has been neglected. Because there are lots of good people, so they do not want to give reference to my papers even though they have not solved the problem of quantum Hall effect and we have.Comment: 4 pages Te

    Quasiparticles in quantum Hall effect: Smet's fractional charge

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    It has been pointed out by Smet that there are fractional-charge values which do not fit with their formula of composite fermions. We find that our formula predicts these fractional charges very well and in fact there exists a relationship between spin and charge of a quasiparticle.Comment: 4 pages Te

    Fractional Charge Experiments: What quantity is measured in quantum Hall effect or calculated by Laughlin?

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    We have examined the experiments performed by Goldman and Su, de-Picciotto et al, Samanadayar et al and Conforti et al in which it is claimed that a fractional charge of e/3 is found. In all of the measurements, the quantity measured is the product of the charge and the magnetic field but not the charge. It is possible to interpret that charge per unit area has been measured, where the area is the square of the magnetic length. This type of correction to Laughlin's result does not affect the exactness of the calculation. Anderson has suggested the extension of Laughlin's state to particles of charge 2/m or 3/m with m=odd integer. We find that the quasiparticle charge depends on the angular momenta, e_{eff}/e=({\it l}+(1/2)\pm s)/(2{\it l}+1) which agrees with the data. Therefore, Laughlin's 1/odd becomes an angular momentum so the charge depends on spin, s.Comment: 7 pages Te

    A new phase in the bilayers of semiconductors in quantum Hall effect

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    We find that a bilayer of semiconductors emits a new Goldstone quasiparticle when Landau levels in the layers are half filled. The emission of the new quasiparticle is associated with the divergence in the energy of the system characteristic of a phase transition. There is a Bose condensation of the pairs of quasiparticles in which one electron has spin up and the other down but the orbital magnetic quantum number is very large so that the spin singlet is very different from the Cooper pairs.Comment: 13 pages Te

    Vortices in Bose-Einstein Condensed Na Atoms

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    There are surface modes on the Bose-Einstein condensed Na atoms so that the number of vortices diverges when the stirring frequency becomes equal to that of the surface waves. We introduce the finite life time of the surface modes so that the number of vortices becomes finite. Usually the number of vortices is a linear function of the stirring frequency. We find that this linearity is destroyed by the finite life time and a peaked function emerges with several peaks, one for each surface mode. The vortices become normal, as they should be, so that there occurs a phase transition from normal to the superfluid state.Comment: 4 page

    Comments on "Mutually composite fermions in double layer quantum Hall systems", Jinwu Ye, cond-mat/0302558: Why is it wrong?

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    Jinwu Ye has shown that two flux quanta are attached in one layer while the electron is in the other layer to form a mutually composite fermion (MCF). This idea is based on an earlier idea that CF are formed by attaching two flux quanta to one electron. We find that the formation of MCF is unphysical and it can not be the basis of a new theory. Similarly, the CF are also unphysical objects and their Lorentz invariance is missing.Comment: 3 pages Te

    Comments on ``Evidence of Landau Levels and Interactions in Low-Lying Excitations of Composite Fermions ..." by Dujovne, Pinczuk, Kang, Dennis, Pfeiffer and West, cond-mat/0211022

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    Dujavne et al suggest that the observed spectra are a result of spin-split Landau levels and spin-flip energies reveal composite fermion interactions. We find that the CF effective field formula is incorrect. In fact, CF model is independent of spin so that the interpretations of data by Dujovne et al in terms of CF model are incorrect. It may be pointed out that the experimental mass of the quasiparticles is several orders of magnitude smaller than the CF mass.Comment: 5 pages Te

    Fractional charge in quantum Hall effect

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    In 1976 Jackiw and Rebbi found 1/2 of a fermion number by using Dirac equation in 1+1 dimensions. Schrieffer in several proposals made an effort to suggest that there is a fractional charge. The calculations of Peierls distortion, Berry's phase and classical action were presented to accomodate the fractional charge in non-relativistic theory. Laughlin used the antisymmetry to define the charge density per unit area in a two dimensional system. In order to elliminate the area, Laughlin introduced the incompressibility which fixed the area so that the odd number, which determines the antisymmetry of the electron wave function, gave the charge. We have used the orbital angular momentum and the spin to define the charge, in full agreement with the quantum Hall effect data.Comment: 6 pages Te
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