Large Conductance Variations in a Mechanosensitive Single-Molecule Junction

Large Conductance Variations in a Mechanosensitive Single-Molecule Junction

Stefani, D. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft)
Weiland, Kevin J. (University of Basel)
Skripnik, Maxim (Okinawa Institute of Science and Technology Graduate University; Universität Konstanz)
Hsu, C. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft)
Perrin, M.L. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft; Swiss Federal Laboratories for Materials Science and Technology (Empa))
Mayor, Marcel (Karlsruhe Institut für Technologie; Sun Yat-sen University; University of Basel)
Pauly, Fabian (Okinawa Institute of Science and Technology Graduate University; Universität Konstanz)
van der Zant, H.S.J. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft)

2018

An appealing feature of molecular electronics is the possibility of inducing changes in the orbital structure through external stimuli. This can provide functionality on the single-molecule level that can be employed for sensing or switching purposes if the associated conductance changes are sizable upon application of the stimuli. Here, we show that the room-temperature conductance of a spring-like molecule can be mechanically controlled up to an order of magnitude by compressing or elongating it. Quantum-chemistry calculations indicate that the large conductance variations are the result of destructive quantum interference effects between the frontier orbitals that can be lifted by applying either compressive or tensile strain to the molecule. When periodically modulating the electrode separation, a conductance modulation at double the driving frequency is observed, providing a direct proof for the presence of quantum interference. Furthermore, oscillations in the conductance occur when the stress built up in the molecule is high enough to allow the anchoring groups to move along the surface in a stick-slip-like fashion. The mechanical control of quantum interference effects results in the largest-gauge factor reported for single-molecule devices up to now, which may open the door for applications in, e.g., a nanoscale mechanosensitive sensing device that is functional at room temperature.

density functional theory
mechanically controlled break-junctions
molecular electronics
nanoscale transport
Quantum interference
single-molecule

http://resolver.tudelft.nl/uuid:5155eb9d-f2cc-4489-8f98-51ae6c83a149

https://doi.org/10.1021/acs.nanolett.8b02810

1530-6984

Nano Letters: a journal dedicated to nanoscience and nanotechnology, 18 (9), 5981-5988

Institutional Repository

journal article

© 2018 D. Stefani, Kevin J. Weiland, Maxim Skripnik, C. Hsu, M.L. Perrin, Marcel Mayor, Fabian Pauly, H.S.J. van der Zant