Heimerl J, Higuchi T, Ammon MM, Schneider MA, Hommelhoff P (2020)
Publication Type: Journal article
Publication year: 2020
Book Volume: 101
Article Number: 125403
Journal Issue: 12
DOI: 10.1103/PhysRevB.101.125403
When nanometric metal structures are illuminated with light, large optical near fields arise. These fields are even further enhanced when two nanometer-sized structures are brought in nanometric distance. Then the individual near fields of the structures couple. Measuring the coupled optical near fields directly is hard. Here we demonstrate an scanning tunneling microscope-based setup which allows us to probe the coupling of optical near fields from two nanometer-sharp metal needles facing each other. By measuring the emitted photocurrent as a function of the gap distance, we retrieve the peak fields at the tip apices. The comparison to optical near-field simulations shows that large field enhancement of 15.9 is present at the tip apex. This is an enhancement 4-times larger compared to the individual nanotip. The demonstrated sensitivity of the coupling on the gap size is of large interest for future applications in ultrafast near-field microscopy.
APA:
Heimerl, J., Higuchi, T., Ammon, M.M., Schneider, M.A., & Hommelhoff, P. (2020). Gap-size dependence of optical near fields in a variable nanoscale two-tip junction. Physical Review B, 101(12). https://dx.doi.org/10.1103/PhysRevB.101.125403
MLA:
Heimerl, Jonas, et al. "Gap-size dependence of optical near fields in a variable nanoscale two-tip junction." Physical Review B 101.12 (2020).
BibTeX: Download