Characterization of quantum conducting channels in metal/molecule/metal devices using pressure-modulated conductance microscopy

摘要

Nanoscale switches will play a crucial role in the design of future nanoelectronic circuits. An interesting candidate involves metal/molecule/metal structures that operate via modulation of nanoscale conducting channels. When the conductance falls in the ballistic regime between 1∼2G _Q (where G _Q =2e 2/h or ≈80 μS), resonant electron transport was observed in such devices at room temperature. By performing pressure-modulated conductance microscopy, we have characterized the quantum conducting channels in terms of the wave vector of the electrons. We also observed two-level fluctuations in conductance, with each level showing opposite pressure responses, confirming the existence of resonant electron transport. These observations could lead to a new type of high speed quantum switching device based on electron wave interference.