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T. C. Vasconcelos

Publications and source records attributed to T. C. Vasconcelos.

3 recordsLinked to original sources

Spin Hall angle fluctuations in a disorder device

We investigate a disorderly mesoscopic device that supports spin-orbit interaction. The systemis connected to four semi-infinite leads embedded in the Landauer-Buttiker setup for quantumtransport and, according to our analysis, exhibits spin Hall angle fluctuations. We show analyticallyand numerically the fingerprint of the universal fluctuation of the polarization mediated by theconversion of charge current into spin current. Our investigation shows the complete compatibilityof our analytical and numerical results with the most recent experiments. Furthermore, we shownonzero and universal features of spin Hall effect in Rashba 2DEG with disorder. All the resultsshow the relevance of microscopic parameters for electronic transport with charge-spin conversionand, in many cases, inevitably lead to universal numbers.

cond-mat.mes-hall

Spin-to-Charge Conversion in 2D Electron Gas and Single-layer Graphene Devices

We investigate the spin-to-charge conversion emerging from a mesoscopic device connected to multiple terminals. We obtain analytical expressions to the characteristic coefficient of spin-to-charge conversion which are applied in two kinds of ballistic chaotic quantum dots at low temperature. We perform analytical diagrammatic calculations in the universal regime for two-dimensional electron gas and single-layer graphene with strong spin-orbit interaction in the universal regime. Furthermore, our analytical results are confirmed by numerical simulations. Finally, we connect our analytical finds to recent experimental measures giving a conceptual explanation about the apparent discrepancies between them.

cond-mat.mes-hall

Universal Spin Hall Conductance Fluctuations in Chaotic Dirac Quantum Dots

We present complete analytical and numerical results that demonstrate the anomalous universal fluctuations of the spin-Hall conductance in chiral materials such as graphene and topological insulators. We investigated both the corresponding fluctuations, the Universal Fractionated and the Universal Quantized, and also the open channels orbital number crossover between the two regimes. In particular, we show that the Wigner-Dyson symmetries does not properly describe such conductances and the preponderant role of the chiral classes on the Dirac quantum dots. The results are analytical and solve outstanding issues.

cond-mat.mes-hall