Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 42: Other Transport Topics

TT 42.8: Talk

Wednesday, March 11, 2026, 11:30–11:45, HSZ/0105

Reconfigurable Optoelectronics at the Single-Molecule Level — •Atif Ghafoor — Department of Physics, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.

Controlling exciton and its coupling at the single-molecule scale is a fundamental challenge for nanoscale optoelectronics and quantum technologies. The ability to precisely reposition individual atom within a single-molecule to alter transition dipole moment, thereby enabling on-demand switching of light emission, remains an unrealized yet transformative goal in single-molecule optoelectronics. Here, by displacing the central metal atom of a planar phthalocyanine molecule adsorbed on decoupling layer, we demonstrate active control over its transition dipole moment, leading to suppression or enhancement of light emission via scanning tunneling microscopy-induced luminescence. Through this atomic-scale control, we designed a tunable homogenous dimer in three distinct optical states: a non-emissive state, a single-molecule-like emissive state, and a coupled state (subradiant and superradiant modes) directly revealing intermolecular dipole-dipole coupling. Furthermore, we realized a heterodimer, in which resonant energy transfer can be switched on or off simply by controlling the dipole of the acceptor molecule. Our strategy for manipulating transition dipole moment and optical emission, not only enables deeper exploration of plasmon-exciton coupling, tunable dipole-dipole interaction, and tunable energy transfer dynamics at the single-molecule level but also stimulates the development of single-molecule quantum engineering and atomically reconfigurable optoelectronic devices.

Keywords: Single-molecule optoelectronics; Plasmon-exciton coupling; Tunable dipole-dipole interaction; Tunable energy transfer; Single-molecule quantum engineering