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تسجيل مستخدم جديدConductivity of Paired Composite Fermions
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We develop a phenomenological description of the nu=5/2 quantum Hall state in which the Halperin-Lee-Read theory of the half-filled Landau level is combined with a p-wave pairing interaction between composite fermions (CFs). The electromagnetic response functions for the resulting mean-field superconducting state of the CFs are calculated and used in an RPA calculation of the q and omega dependent longitudinal conductivity of the physical electrons, a quantity which can be measured experimentally.
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The relation between the conductivity tensors of Composite Fermions and electrons is extended to second generation Composite Fermions. It is shown that it crucially depends on the coupling matrix for the Chern-Simons gauge field. The results are appl
ied to a model of interacting Composite Fermions that can explain both the anomalous plateaus in spin polarization and the corresponding maxima in the resistivity observed in recent transport experiments.
When interacting two-dimensional electrons are placed in a large perpendicular magnetic field, to minimize their energy, they capture an even number of flux quanta and create new particles called composite fermions (CFs). These complex electron-flux-
bound states offer an elegant explanation for the fractional quantum Hall effect. Furthermore, thanks to the flux attachment, the effective field vanishes at a half-filled Landau level and CFs exhibit Fermi-liquid-like properties, similar to their zero-field electron counterparts. However, being solely influenced by interactions, CFs should possess no memory whatever of the electron parameters. Here we address a fundamental question: Does an anisotropy of the electron effective mass and Fermi surface (FS) survive composite fermionization? We measure the resistance of CFs in AlAs quantum wells where electrons occupy an elliptical FS with large eccentricity and anisotropic effective mass. Similar to their electron counterparts, CFs also exhibit anisotropic transport, suggesting an anisotropy of CF effective mass and FS.
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Each end of a Kitaev chain in topological phase hosts a Majorana fermion. Zero bias conductance peak is an evidence of Majorana fermion when the two Majorana fermions are decoupled. These two Majorana fermions are separated in space and this nonlocal
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