# Synopsis: Tuning conductance

A single-molecule junction on a silver surface exhibits orders-of-magnitude variation in conductance.

Electron transport through molecules has implications for a range of subjects. In particular, conductance through single-molecule junctions is known to have a complex dependence on atomic structure, orientation, and bonding properties. However, investigations with atomic-scale control of the junction geometry are scarce.

In their paper in Physical Review Letters, Yongfeng Wang and collaborators from Germany, Denmark, and Sweden demonstrate that the conductance in a single-molecule junction varies over orders of magnitude.

Wang et al. present scanning tunneling microscopy measurements of the conductance of tin-phthalocyanine ($\text{SnPc}$) adsorbed on a $\text{Ag}\left(111\right)$ surface in contact with a tungsten tip covered with silver. By manipulating the chemical bonding between $\text{SnPc}$ and $\text{Ag}\left(111\right)$ through selective dehydrogenation of $\text{SnPc}$ and an atomic-scale structuring of the electrode, the conductance of single-molecule junctions is varied from $0.013$ to $0.32$ in units of the quantum of conductance. The authors also perform ab initio calculations combined with a nonequilibrium Green’s function technique for a quantitative analysis of the electron transport through $\text{Ag-SnPc-Ag}$ junctions. This opens an avenue to study current flow through single molecules by combining transport measurements with atomic manipulation capabilities of the scanning tunneling microscope. – Sarma Kancharla

### Announcements

More Announcements »

Nuclear Physics

Gravitation

## Related Articles

Atomic and Molecular Physics

### Viewpoint: Superfluids Hit the Street

A flow pattern dubbed the von Kármán vortex street, which is renowned for its aesthetic beauty and extreme power, has been created in a superfluid. Read More »

Atomic and Molecular Physics

### Viewpoint: Lamb Shift Spotted in Cold Gases

Cold atomic gases exhibit a phononic analog of the Lamb shift, in which energy levels shift in the presence of the quantum vacuum. Read More »

Atomic and Molecular Physics

### Synopsis: Quantum Droplets Swell to a Macrodrop

Experiments with ultracold magnetic atoms reveal liquid-like quantum droplets that are 20 times larger than previously observed droplets.    Read More »