Molecular Mechano-Electronics

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Adapted from
“Mechanical Control of Spin States
in Spin-1 Molecules and the Underscreened Kondo Effect”
J. J. Parks et al., Science, 328:1370–1373 (2010).

Pulling on the ends of a cobalt complex that bridges an electrical junction (as illustrated) changes the geometry of the coordinating ligands, hence the energies of electronic spin states, hence (as it turns out) the low-temperature electrical resistance of the junction. The authors of the paper cited here look toward potential applications for devices that manipulate spin states mechanically:

…Our work further demonstrates that mechanical control can be a realistic strategy for manipulating molecular spin states to supplement or replace the use of magnetic fields in proposed applications such as quantum manipulation or information storage.
(Science,June 2010)

Whether or not their approach is practical, this paper is a reminder that almost all molecular properties are sensitive to mechanical effects, and sometimes in important ways. Modulating chemical reactivity and selecting among reaction sites are basic and obvious examples of molecular mechanical effects, but the general class can be anticipated to be as broad as the effects of temperature or pressure.

• Mechanochemistry, Mechanosynthesis, and Molecular Machinery
• The Physical Basis of Atomically Precise Manufacturing
• Productive nanosystems: the physics of molecular fabrication [pdf]
  (from the Institute of Physics journal, Physics Education)
• Molecular Nanomachines: Physical Principles and Implementation Strategies (from the Annual Review of Biophysics and Biomolecular Structure)

Tagged as: molecular electronics, nanomachines, quantum computing