Oxygen-activated Growth and Bandgap Tunability of Large Single-Crystal Bilayer Graphene

June 1, 2016

Fig. 2: BLG domain size and stacking order control*
[Reprinted by permission from Macmillan Publishers Ltd: Nature Nanotechnology ©2016]

Bernal (AB)-stacked bilayer graphene (BLG) is a semiconductor whose bandgap can be tuned by a transverse electric field, making it a unique material for a number of electronic and photonic devices. A scalable approach to synthesize high-quality BLG is therefore critical and requires minimal crystalline defects in both graphene layers and maximal area of Bernal stacking, which is necessary for bandgap tunability.


Bloch State Tomography Using Wilson Lines

May 27, 2016

Fig. 1b: Wilson lines and effectively degenerate Bloch bands.* [Reprinted with permission from AAAS ©2016.]

Topology and geometry are essential to our understanding of modern physics, underlying many foundational concepts from high-energy theories, quantum information, and condensed-matter physics. In condensed-matter systems, a wide range of phenomena stem from the geometry of the band eigenstates, which is encoded in the matrix-valued Wilson line for general multiband systems.