Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic Characterization of a Charge-Transfer Complex Monolayer on
  Graphene   Organic charge-transfer complexes (CTCs) formed by strong electron acceptor
and strong electron donor molecules are known to exhibit exotic effects such as
superconductivity and charge density waves. We present a low-temperature
scanning tunneling microscopy and spectroscopy (LT-STM/STS) study of a
two-dimensional (2D) monolayer CTC of tetrathiafulvalene (TTF) and fluorinated
tetracyanoquinodimethane (F4TCNQ), self-assembled on the surface of
oxygen-intercalated epitaxial graphene on Ir(111) (G/O/Ir(111)). We confirm the
formation of the charge-transfer complex by dI/dV spectroscopy and direct
imaging of the singly-occupied molecular orbitals. High-resolution spectroscopy
reveals a gap at zero bias, suggesting the formation of a correlated ground
state at low temperatures. These results point to the possibility to realize
and study correlated ground states in charge-transfer complex monolayers on
weakly interacting surfaces.

10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
2
The categories of this paper are: math
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph