Khanikaev, A. B.
Arju, N.
Fan, Z.
Purtseladze, D.
Lu, F.
Lee, J.
Sarriugarte, P.
Schnell, M.
Hillenbrand, R.
Belkin, M. A.
Shvets, G.
Article History
Received: 16 September 2015
Accepted: 25 May 2016
First Online: 22 June 2016
Competing interests
: R.H. is co-founder of Neaspec GmbH, a company producing scattering-type scanning near-field optical microscope systems, such as the one used in this study. The remaining authors declare no competing financial interests.