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تسجيل مستخدم جديدOn the Interpretation of Thermal Conductance of the nu=5/2 Edge
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Steven H. Simon
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Recent experiments [Banerjee et al, arXiv:1710.00492] have measured thermal conductance of the nu=5/2 edge in a GaAs electron gas and found it to be quantized as K approx 5/2 (in appropriate dimensionless units). This result is unexpected, as prior numerical work predicts that the nu=5/2 state should be the Anti-Pfaffian phase of matter, which should have quantized K=3/2. The purpose of this paper is to propose a possible solution to this conflict: if the Majorana edge mode of the Anti-Pfaffian does not thermally equilibrate with the other edge modes, then K=5/2 is expected. I briefly discuss a possible reason for this nonequilibration, and what should be examined further to determine if this is the case.
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We address the interpretation proposed in [S. H. Simon, arXiv:1801.09687] of the thermal conductance data from [M. Banerjee et al., arXiv:1710.00492]. We show that the interpretation is inconsistent with experimental data and the sample structure. In
particular, the paper misses the momentum mismatch between contra-propagating modes. Contrary to the claim of the paper, low energy tunneling involves a large momentum change. We consider only the small Majorana velocity mechanism [S. H. Simon, arXiv:1801.09687]. Other mechanisms, interpretations of the experiment, and their difficulties are beyond the scope of this Comment.
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all effect with a quantized conductivity at an unusual half-integer nu=5/2 Landau level filling. Here we show that similar electron pairing may occur in quantum dots where the gas of electrons is trapped by external electric potentials into small quantum Hall droplets. However, we also find theoretical and experimental evidence that, depending on the shape of the external potential, the paired electron state can break down, which leads to a fragmentation of charge and spin densities into incompressible domains. The fragmentation of the quantum Hall states could be an issue in the proposed experiments that aim to probe for non-abelian quasi-particle characteristics of the nu=5/2 quantum Hall state.
Recent schemes for experimentally probing non-abelian statistics in the quantum Hall effect are based on geometries where current-carrying quasiparticles flow along edges that encircle bulk quasiparticles, which are localized. Here we consider one su
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