Entanglement between static and flying qubits in a semiconducting carbon nanotube

TL;DR

This paper demonstrates how entanglement between static and flying electrons can be generated and controlled in a semiconducting carbon nanotube, with potential applications in quantum information processing.

Contribution

It introduces a method to generate and tune entanglement between static and flying qubits in a carbon nanotube using Coulomb interaction and gate control.

Findings

Entanglement depends on well characteristics and electron energy.

Full or partial entanglement regimes are identified.

Maximum entanglement relates to singlet-triplet resonance parameters.

Abstract

Entanglement can be generated by two electrons in a spin-zero state on a semiconducting single-walled carbon nanotube. The two electrons, one weakly bound in a shallow well in the conduction band, and the other injected into the conduction band, are coupled by the Coulomb interaction. Both transmission and entanglement are dependent on the well characteristics, which can be controlled by a local gate, and on the kinetic energy of the injected electron. Regimes with different degrees of electron correlation exhibit full or partial entanglement. In the latter case, the maximum entanglement can be estimated as a function of width and separation of a pair of singlet-triplet resonances.