Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of Nanometer-Scale Rolling Motion Mediated by Commensurate
  Contact   We report, through experimental observations and computer simulations, that
atomic lattice interlocking can determine whether an object rolls or slides on
a surface. We have quantitatively manipulated carbon nanotubes (CNTs) on a
variety of substrates with an atomic force microscope (AFM) and observe rolling
to occur only on graphite. We measure the forces when the CNT is in-registry
with the graphite lattice, and observe rolling only in this lock-in state.
Atomistic computer simulations identify the energy barriers for sliding and
rolling, elucidate atomic-scale features of slip-roll motion, and explain the
details of the lateral force data in terms of the intrinsic faceting of
multiwall CNTs.

17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph