Figure 4
From: Controlling single-molecule junction conductance by molecular interactions
Calculation of the environmental effect for different dimer junction geometries.
(a–c) Side views of (2,0), (2,1) and (2,2) dimer junction geometries with one molecule lifted up by the STM tip. (d–f) The changes in the electrostatic potential (δV) induced by a neighbor phenoxy molecule in the dimer junction geometries. (g–i) Top views of (2,0), (2,1) and (2,2) dimer junction geometries. (j–l) Corresponding changes in the electrostatic potential. The tip height h = 13.9 Å and lateral position x = 1.4 Å. The projections are onto planes through the center of the conducting molecule (to the left in each visualization). Contour lines are separated by 25 meV. Blue (red) areas indicate a positive (negative) change in potential and the thick contour line the zero-value. Atomic positions are shown as colored circles (blue: Cu, gray: H, orange: C, red: O). White lines in (j–l) indicate the Cu(110) lattice. (m) Transmission and (n) projected density of states (PDOS) onto the Cu apex atom as well as onto the atoms in the current-carrying phenoxy molecule [thick lines: monomer; red dashed: (2,0); blue: (2,1); green: (2,2) configurations]. Tiny shifts of the resonances to lower energies are observed in the dimer configurations. For the (2,0)-dimer the transmission probability near the Fermi level T(EF) and hence the low-bias conductance, is lowered with respect to the other configurations.
