Rights:
© 2011 American Physical Society (APS). This is the accepted version of the following article: Sillanpää, Mika A. & Khan, Raphaël & Heikkilä, Tero T. & Hakonen, Pertti J.. 2011. Macroscopic quantum tunneling in nanoelectromechanical systems. Physical Review B. Volume 84, Issue 19. 195433/1-7. ISSN 1098-0121 (printed). DOI: 10.1103/physrevb.84.195433, which has been published in final form at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.84.195433.