Gapping by squashing: metal-insulator and insulator-metal transitions in collapsed carbon nanotubes
Squashing brings circumferentially separated areas of a carbon nanotube into close proximity, drastically altering the low-energy electronic properties and (in some cases) reversing standard rules for metallic versus semiconducting behavior. Such a deformation mode, not requiring motion of tube ends, may be useful for devices. Uniaxial stress of a few kbar can reversibly collapse a small-radius tube, inducing a 0.1 eV gap with a very strong pressure dependence, while the collapsed state of a larger tube is stable. The low-energy electronic properties of chiral tubes are surprisingly insensitive to collapse.
Lammert
PE
Department of Physics and Center for Materials Physics, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802, USA.
Zhang
P
Crespi
VH