Barbosa A L R, Bazeia D, Ramos J G G S
Departamento de Física, Universidade Federal Rural de Pernambuco, 52171-900 Recife, Pernambuco, Brazil.
Departamento de Física, Universidade Federal da Paraíba, 58051-970 Joaão Pessoa, Paraíba, Brazil.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Oct;90(4):042915. doi: 10.1103/PhysRevE.90.042915. Epub 2014 Oct 17.
We present analytical and numerical results that demonstrate the presence of the Braess paradox in chaotic quantum dots. The paradox that we identify, originally perceived in classical networks, shows that the addition of more capacity to the network can suppress the current flow in the universal regime. We investigate the weak localization term, showing that it presents the paradox encoded in a saturation minimum of the conductance, under the presence of hyperflow in the external leads. In addition, we demonstrate that the weak localization suffers a transition signal depending on the overcapacity lead and presents an echo on the magnetic crossover before going to zero due to the full time-reversal symmetry breaking. We also show that the quantum interference contribution can dominate the Ohm term in the presence of constrictions and that the corresponding Fano factor engenders an anomalous behavior.
我们展示了分析和数值结果，这些结果证明了混沌量子点中存在布雷斯悖论。我们所识别的这个悖论最初是在经典网络中发现的，它表明在通用 regime 中给网络增加更多容量可能会抑制电流流动。我们研究了弱局域化项，表明在外部引线存在超流的情况下，它呈现出以电导饱和最小值编码的悖论。此外，我们证明弱局域化会根据过容量引线出现转变信号，并且在由于完全时间反演对称性破缺而趋于零之前，在磁交叉处呈现出一个回波。我们还表明，在存在收缩的情况下，量子干涉贡献可以主导欧姆项，并且相应的法诺因子会产生异常行为。
