Molecular transport and spectroscopy in plasmonic nanojunctions

This project is focused on fundamental studies of molecular nanojunctions by combining electronic transport and optical spectroscopy techniques. We use a mechanically controlled break-junction (MCBJ, Fig. 1) to actuate plasmonic bowtie nano-antennas with sub-1-nm, tunable gaps, which is suitable for dynamic surface enhanced Raman scattering (SERS) studies. We also fabricate novel molecular nanojunctions using laser printing and evaporation techniques (Fig. 2). Our system is carefully designed to combine transport and spectroscopy measurements. We want to probe in situ and in real time the vibrational and charge dynamics of single or few molecules embedded in plasmonic nanocavities, which will provide a better understanding of some fundamental aspects of SERS and molecular optomechanics. Furthermore, we intend to drive molecular vibrations out of equilibrium via electrical and optical means.

PhD student: Sakthi Priya Amirtharaj

Collaboration: Dr. Emanuel Loertscher, IBM Research Switzerland


[1] C.M. Gruber et al. Nano Letters 20, 6, 4346–4353 (2020) (

Funding: ERC Consolidator Grant QTONE

Fig. 1: mechanically controlled break-junction  
Fig. 2: Molecular junction with single plasmonic nanoparticle