Abstract
Molecular vibrational spectroscopy with the scanning tunneling microscope is feasible but usually detects few vibrational modes. We harness sharp Yu-Shiba-Rusinov states observed from molecules on a superconductor to significantly enhance the vibrational signal. From a lead phthalocyanine molecule 46 vibrational peaks are resolved enabling a comparison with calculated modes. The energy resolution is improved beyond the thermal broadening limit and shifts induced by neighbor molecules or the position of the microscope tip are determined. Vice versa, spectra of vibrational modes are used to measure the effect of an electrical field on the energy of Yu-Shiba-Rusinov states. The method may help to further probe the interaction of molecules with their environment and to better understand selection rules for vibrational excitations.
- Received 16 February 2022
- Revised 13 April 2022
- Accepted 13 July 2022
DOI:https://doi.org/10.1103/PhysRevLett.129.116801
© 2022 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Superconductors Give STM a Boost
Published 7 September 2022
Using superconducting materials can increase the strength of scanning-tunneling-spectroscopy signals by up to a factor of 50, allowing the detection of tiny changes in a single molecule’s vibrational energy.
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