Single Carbon Nanotube--Superconductor Entangler: noise correlations and EPR states

TL;DR

This paper proposes a nanostructured device using a carbon nanotube and superconductor to generate and detect entangled electrons and noise correlations, advancing solid-state quantum information technologies.

Contribution

It introduces a novel device design for electron entanglement and noise correlation detection using a carbon nanotube-superconductor system, with specific setups for spin and energy filtering.

Findings

Demonstrates positive noise correlations in a fermionic system.

Provides a method to generate entangled electrons via spin or energy filters.

Suggests feasible fabrication techniques for the proposed device.

Abstract

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.