Preparation of cluster states with endohedral fullerenes in single-walled carbon nanotubes

Abstract

We propose two scalable methods for generation of cluster states with arrays of endohedral fullerenes 15N@C60 residing in single-walled carbon nanotubes (SWCNTs) using direct and indirect methods, respectively. The direct method makes use of a series of controlled-phase flip (CPF) gates by electron spin resonance pulses of selective frequencies and durations, where the CPF gates are realized by magnetic-dipole couplings between the electron spins of the nearest-neighbour fullerenes in SWCNTs. The indirect method resorts to auxiliary mobile electron as the flying qubit, which transfers quantum information from one site to another. This greatly releases the requirements for the distance between fullerenes in SWCNTs. The decoherence effect and experimental feasibility are also discussed based on currently available technology.