Two-Terminal Molecular Memory via Reversible Switching of Quantum Interference Features in Tunneling Junctions.

Two-Terminal Molecular Memory via Reversible Switching of Quantum Interference Features in Tunneling Junctions.
Angew Chem Int Ed Engl. 2018 Sep 27;:
Authors: Carlotti M, Soni S, Kumar S, Ai Y, Sauter E, Zharnikov M, Chiechi RC
Abstract
This paper describes large-area molecular tunneling junctions comprising self-assembled monolayers of redox-active molecules that exhibit two-terminal bias switching. The as-prepared monolayers undergo partial charge-transfer to the underlying metal substrate (Au, Pt or Ag) that converts their cores from a quinoid to hydroquinoid form. The resulting rearomatization converts the bond topology from a cross-conjugated to linearly-conjugated π system. The cross-conjugated form correlates to appearance of an interference feature in the transmission spectrum that vanishes in the linear-conjugated form. Due to the presence of electron-withdrawing nitrile groups, the reduction potential and the interference feature lie close the work function and Fermi level of the metallic substrate. The relationship between conjugation patterns and quantum interference is well-studied. We exploit this relationship to create non-volatile memory in proto-devices using eutectic Ga-In as the top-contact. The underlying switching mechanism reorders bond topology without changing connectivity or altering the tunneling distance or thickness of the monolayer. These results are a proof-of-concept for switching quantum interference ...

Source: Angewandte Chemie - September 27, 2018 Category: Chemistry Authors: Carlotti M, Soni S, Kumar S, Ai Y, Sauter E, Zharnikov M, Chiechi RC Tags: Angew Chem Int Ed Engl Source Type: research