A quantum spin transducer based on nanoelectromechanical resonator arrays

• Published in: Nature physics Vol. 6; no. 8; pp. 602 - 608
• Main Authors: Rabl, P, Kolkowitz, S. J, Koppens, F. H. L, Harris, J. G. E, Zoller, P, Lukin, M. D
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-08-2010; Nature Publishing Group
• Subjects: Arrays; Atomic; Classical and Continuum Physics; Coherence length; Complex Systems; Condensed Matter Physics; Electronics; Information technology; Magnetic fields; Mathematical and Computational Physics; Mechanical systems; Molecular; Nanomaterials; Nanostructure; Optical and Plasma Physics; Physics; Physics and Astronomy; Quantum physics; Qubits (quantum computing); Resonators; Theoretical; Transducers
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/nphys1679

Isolated electronic and nuclear spins in solids are at present being actively explored for potential quantum-computing applications. Spin degrees of freedom provide an excellent quantum memory, owing to their weak magnetic interactions with the environment. For the same reason, however, it is difficult to achieve controlled interactions of spins over distances larger than tens of nanometres. Here we propose a new realization of a quantum data bus for spin qubits where spins are coupled to the motion of magnetized mechanical resonators through magnetic-field gradients. Provided that the mechanical system is charged, the magnetic moments associated with spin qubits can be effectively amplified to enable a coherent spin–spin coupling over long distances through Coulomb forces. Our approach is applicable to a wide class of electronic spin qubits, which can be localized near magnetized tips and can be used for the implementation of hybrid quantum-computing architectures.
In a quantum computer, the data carriers (or qubits) must be well isolated from their environment to avoid information leakage. At the same time they have to interact with one another to process information. A proposed platform based on spin qubits connected through arrays of nanoelectromechanical resonators should be able to reconcile these conflicting requirements.