We report a theoretical study suggesting a novel type of electronic switching effect, driven by the geometrical reconstruction of nanoscale graphene-based junctions. We considered junction struc- tures which have alternative metastable configurations transformed by rotations of local carbon dimers. The use of external mechanical strain allows a control of the energy barrier heights of the potential profiles and also changes the reaction character from endothermic to exothermic or vice-versa. The reshaping of the atomic details of the junction encode binary electronic ON or OFF states, with ON/OFF transmission ratio that can reach up to 10^4-10^5. Our results suggest the possibility to design modern logical switching devices or mechanophore sensors, monitored by mechanical strain and structural rearrangements.
Prevailing models of resistive switching arising from electrochemical formation of conducting filaments across solid state ionic conductors commonly attribute the observed polarity of the voltage-biased switching to the sequence of the active and inert electrodes confining the resistive switching memory cell. Here we demonstrate equivalent, stable switching behavior in metallic Ag-Ag$_{2}$S-Ag nanojunctions at room temperature. Our experimental results and numerical simulations reveal that the polarity of the switchings is solely determined by the geometrical asymmetry of the electrode surface…
Understanding the process of electron tunneling in chirality-induced single-molecule junctions is imperative for the development of nanoscale switching and artificial nanomotors. Based on the combined non-equilibrium Green functions formalism and the ground-state density functional theory, we present here the charge transport behavior of chiral gold (7,3) nanowires (NWs) in comparison with various other chiral and achiral 1D gold nanostructures as the principal leads to form stable single-molecule junctions. For sigma-saturated alkane chains, we find that the contact potential barriers vary wi…
We investigate gold-4,4'-bipyridine-gold single-molecule junctions with the mechanically controllable break junction technique at cryogenic temperature ($T=4.2\,\text{K}$). We observe bistable probabilistic conductance switching between the two molecular binding configurations, influenced both by the mechanical actuation, and the applied voltage. We demonstrate that the relative dominance of the two conductance states is tunable by the electrode displacement, whereas the voltage manipulation induces an exponential speedup of both switching times. The detailed investigation of the voltage-tunab…
Memristive Switches in Rigid Conjugated Single-Molecule Junctions
Delft University of Technology（代尔夫特理工大学）；Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学卡弗里纳米科学研究所）；Polish Academy of Sciences（波兰科学院）；Institute of Organic Chemistry, Polish Academy of Sciences（波兰科学院有机化学研究所）
We explore the thermoelectric properties of gold atomic chains bridging gold electrodes by means of \textit{ab initio} and semi-empirical calculations, and heuristic reasoning. We predict the thermoelectric voltage induced by a temperature difference across such junctions to oscillate, repeatedly changing sign, as a function of the number of atoms $N$ making up the atomic chain. We also predict the amplitude of the oscillations to be proportional to $N$ for long atomic chains. Further we predict the thermoelectric voltage to change sign, in some cases, if the junction is stretched without chan…
The appealing feature of molecular electronics is the possibility of exploiting functionality built within a single molecule. This functionality can be employed, for example, for sensing or switching purposes. Thus, ideally, the associated conductance changes should be sizable upon application of external stimuli. Here, we show that a molecular spring can be mechanically compressed or elongated to tune its conductance by up to an order of magnitude by controlling the quantum interference between electronic pathways. Oscillations in the conductance occur when the stress built up in the molecule…
