Today, our paper on strained induced scalar potential in graphene appeared, see: publication. When graphene is uniaxially strained, the unit cell is elongated which leads to a chnage in the binding energy. This change has the same effect as an electrostatic potential shift. It amounts to ~40meV per 1% strain for the Fermi energy. This is a large change, exceeding the thermal energy at room temperature. It thus can have wide application in, for example, smart sensor for the “internet of things”. For further reading, see the press release of he University of Basel and the Swiss Nanoscience Institute: UBas-news.

The left figure shows the principle of the strain setup. A pushing wedge bends a thin substrate on which the encapsulated graphene stack resides. The stack is seen on the right. The graphene layer is strained through the two Cr/Au edge contacts.


Picture of an actual bending system that is mounted on a cryostat insert. The pushing wedge is seen “in operation” and the substrate is bent. All machined and designed by the workshop of the Department of Physics, the University of Basel.


Measurement of the strain induced shifts. Here, the electrical conductance is plotted against the back-gate voltage in a quantizing magnetic field for different strain settings (curves with different colours). The shifts are very clear here (along the horizontal axis) and one observes quantized conductance plateau values that are independent of strain, illustrating that the contact resistance is not affected by the strain.
Paper “Global strain-induced scalar potential in graphene devices”