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A. L. R. Barbosa

Publications and source records attributed to A. L. R. Barbosa.

20 records · Page 2Linked to original sources

Presence of asymmetric noise in multi-terminal chaotic cavities

This work deals with chaotic quantum dot connected to two and four leads. We use standard diagrammatic procedure to integrate on the unitary group, to study the main term in the semiclassical expansion of the noise in the three pure Wigner-Dyson ensembles at finite frequency and temperature, in the noninteracting and interacting regimes. We investigate several limits, related to the temperature and the potential difference in the leads, in the presence of a capacitive environment. At the thermal crossover regime, we obtain general expressions described in terms of parameters that can be controlled experimentally. As an interesting result, we show the appearance of asymmetries in the noise, controlled by the topology of the cavity and the number of open channels in the corresponding terminals.

cond-mat.mes-hall↗

Crossover of thermal to shot noise in chaotic cavities

We study the crossover between thermal and shot-noise power in a chaotic quantum dot in the presence of non-ideal contacts at finite temperature. The result explicitly demonstrates that the temperature affect the suppression-amplification effect present in the main quantum noise. In particular, the weak localization contribution to the noise has an anomalous thermal behavior when one let the barriers vary, indicating the presence of a critical point related to specific value of the tunneling barriers. We also show how to get to the opaque limit of the quantum dot at finite temperature.

cond-mat.mes-hall↗