TY - JOUR
T1 - The puzzle of contrast inversion in DNA STM imaging
AU - Shapir, Errez
AU - Yi, Juyeon
AU - Cohen, Hezy
AU - Kotlyar, Alexander B.
AU - Cuniberti, Gianaurelio
AU - Porath, Danny
PY - 2005/8/4
Y1 - 2005/8/4
N2 - DNA has been at the center of an imaging effort since the invention of the scanning tunneling microscope (STM). In some of the STM imaging reports the molecules appeared with negative contrast, i.e., "submerged" under the metal background and darker. We demonstrate the phenomenon of contrast inversion in DNA STM imaging by controlled and spontaneous contrast inversions and by the dependence of the DNA apparent height with respect to the surface on the imaging bias voltage. Using these characterizations, we formulate a model explaining the above phenomenon by resonant tunneling through virtual states in the vacuum between the STM tip and the DNA molecule.
AB - DNA has been at the center of an imaging effort since the invention of the scanning tunneling microscope (STM). In some of the STM imaging reports the molecules appeared with negative contrast, i.e., "submerged" under the metal background and darker. We demonstrate the phenomenon of contrast inversion in DNA STM imaging by controlled and spontaneous contrast inversions and by the dependence of the DNA apparent height with respect to the surface on the imaging bias voltage. Using these characterizations, we formulate a model explaining the above phenomenon by resonant tunneling through virtual states in the vacuum between the STM tip and the DNA molecule.
UR - http://www.scopus.com/inward/record.url?scp=23844483925&partnerID=8YFLogxK
U2 - 10.1021/jp052738e
DO - 10.1021/jp052738e
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C2 - 16852793
AN - SCOPUS:23844483925
SN - 1520-6106
VL - 109
SP - 14270
EP - 14274
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 30
ER -