Mechanically controllable strain junctions: targeting quantum effects and strong plasmonic coupling in ultra-narrow gaps

01/01/2016 to 31/12/2018

In the present work, the approach of using mechanically controllable break junctions (MCBJs), which offers excellent distance control but not very good control of the junction geometry, will be revised by developing mechanically controllable strain junctions (MCSJs). In this configuration the shape of the plasmonic tips in the gap region is lithographically pre-defined on a pre-stretched substrate, which afterwards will be controllably released to approach the tips in a setup similar to the MCBJ. This way, the junction region and the plasmon resonances of the plasmonic tips can be engineered, while feedback-controlled approach to sub-nanometer distances is still available. The configuration will be fabricated, varied and thoroughly optically and electronically characterized. In the last part of the project, molecules will be introduced in the gap for electrical transport and Raman investigations in such ultra small gaps, probing the quantum and tunneling regime.