Hai-Feng Lu, Hai-Zhou Lu, Shun-Qing Shen
Owing to their nonlocality, qubits nested in Majorana bound states may be the key to realize decoherence-free quantum computation. Majorana bound states could be achieved at the ends of a one-dimensional topological superconductor. However, when the bound states couple directly to electron reservoirs their nonlocal correlation is quenched by local Andreev reflections. Here we propose a scheme to generate nonlocal noise cross-correlation between two well-separated quantum dots, mediated by a pair of Majorana bound states. Both positive and negative cross-correlations can be obtained by tuning the gate voltages applied to the dots. Within a limited range of finite temperatures, the cross-correlation is not suppressed by thermal fluctuations. Furthermore, we show how the local Andreev reflections suppress the noise cross-correlation when multiple dot energy levels are coupled to the Majorana bound states. The measurable cross-correlation is expected to serve as a sensitive indicator for the generation of Majorana fermions.
View original:
http://arxiv.org/abs/1208.3070
No comments:
Post a Comment