  We propose a device which implements a solid-state nanostructured electron
entangler. It consists of a single-walled carbon nanotube connected at both end
to normal state electrodes and coupled in its middle part to a superconducting
nanowire. Such a device acts as an electronic beam splitter for correlated
electrons originating from the superconductor. We first show that it can be
used to detect positive (bosonic--like) noise correlations in an fermionic
system. Furthermore, it provides a source for entangled electrons in the two
arms of the splitter. For generating entangled electron states, we propose two
kinds of setup based either on spin or energy filters. It respectively consists
of ferromagnetic pads and of a system of electrostatic gates which define
quantum dots. The fabrication of this device would require state-of-the-art
nanofabrication techniques, carbon nanotube synthesis and integration, as well
as atomic force microscopy imaging and manipulation.
