3:30–4:30 pm Maria Geoppert-Mayer Lecture Hall
No Strain, No Gain: Modifying Transport in 2D Materials by Engineering Strain
Nadya Mason, University of Chicago, PME(Dean)
Applying strain can drastically modify the properties of electronic materials – for example, strained silicon transistors showed huge mobility increases that revolutionized the computer industry. Now, there is wide interest in using strain to modify the next-generation of electronic materials: two-dimensional systems. Two-dimensional materials bridge the limits of superior electric tunability and high mechanical flexibility, making them excellent candidates for mechanical tuning of electronic properties. Strained graphene, in particular, is predicted to manifest a bandgap opening as well as novel physical effects such as large “pseudo”-magnetic fields. However, it is challenging to create global strain across graphene to modify transport. In this talk, we demonstrate how controllable, global strain in graphene can be engineered by depositing graphene on corrugated substrates. We show that strained graphene exhibits bandgap openings and pseudomagnetic field effects that depend on the magnitude of induced strain. Control of the strain degree of freedom provides a novel platform both for fundamental studies of 2D electron correlations and for prospective applications in 2D electronic devices.
Work supported by NSF under DMR-1720633 and DMR-2309037 (MRSEC), the ARO under W911NF-19-1-0346, and the UIUC Materials Research Lab.