- Number 348 |
- October 17, 2011
Scientists detect unusual ‘quasiparticles’ in tri-layer graphene
Liyuan Zhang and Igor Zaliznyak
at Brookhaven Lab’s
By studying three layers of graphene — sheets of honeycomb-arrayed carbon atoms — stacked in a particular way, scientists at Brookhaven Lab have discovered a “little universe” populated by a new kind of “quasiparticles” — particle-like excitations of electric charge. Unlike massless photon-like quasiparticles in single-layer graphene, these new quasiparticles have mass, which depends on their energy (or velocity). In theory, these unique quasiparticles become infinitely massive at rest!
That accumulation of mass at low energies means this trilayer graphene system, if magnetized by incorporating it into a heterostructure with magnetic material, could potentially generate a much larger density of spin-polarized charge carriers than single-layer graphene. That would make this tri-layer graphene very attractive for a new class of devices based on controlling not just electric charge but also spin, commonly known as spintronics.
Sheets of honeycomb-arrayed
carbon atoms stacked offset
from one another like stair steps.
[Karen McNulty Walsh, 631.344.8350,