Single-molecule-resolution ultrafast near-field optical microscopy via plasmon lifetime extension


OVALI R. V. , ŞAHİN R., BEK A., TAŞGIN M. E.

APPLIED PHYSICS LETTERS, vol.118, no.24, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 118 Issue: 24
  • Publication Date: 2021
  • Doi Number: 10.1063/5.0057812
  • Title of Journal : APPLIED PHYSICS LETTERS

Abstract

Metal nanostructures support plasmon oscillations on their surfaces, which normally decay very quickly. Nevertheless, the lifetime of these oscillations can be extended near a longer lifetime particle, e.g., a molecule. We utilize this phenomenon for ultrahigh (single-molecule) resolution ultrafast apertureless (scattering) applications. We demonstrate the phenomenon with the numerical solutions of 3D Maxwell equations. We use a nm-sized quantum emitter (QE) for the long lifetime particle. We place the QE at the apex of a metal-coated atomic force microscope tip. We illuminate the tip with a femtosecond laser. The near-field on the metal apex decays quickly. After some time, one receives the scattering signal only from the vicinity of the QE. Thus, the resolution becomes single-QE size. We propose the use of a stress-induced defect center in a 2D material as the QE. The tip indentation of the 2D material, transferred to the tip, originates a defect center located right at the sharpest point of the tip, which is exactly at its apex. Our method can equally be facilitated for single-molecule-size chemical manipulation.