Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Formation of copper boride on Cu(111)   Boron forms compounds with nearly all metals, with notable exception of
copper and other group IB and IIB elements. Here, we report an unexpected
discovery of ordered copper boride grown epitaxially on Cu(111) under ultrahigh
vacuum. Scanning tunneling microscopy experiments combined with ab initio
evolutionary structure prediction reveal a remarkably complex structure of
2D-Cu8B14. Strong intra-layer p-d hybridization and a large amount of charge
transfer between Cu and B atoms are the key factors for the emergence of copper
boride. This makes the discovered material unique and opens up the possibility
of synthesizing ordered low-dimensional structures in similar immiscible
systems.

32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat