Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two ultra-stable novel allotropes of Tellurium few-layers   At least four two- or quasi-one- dimensional allotropes and a mixture of them
were theoretically predicted or experimentally observed for low-dimensional Te,
namely the {\alpha}, \b{eta}, {\gamma}, {\delta} and chiral-{\alpha}+{\delta}
phases. Among them the {\gamma} and {\alpha} phases were found the most stable
phases for monolayer and thicker layers, respectively. Here, we found two novel
low-dimensional phases, namely the {\epsilon} and {\zeta} phases. The {\zeta}
phase is over 29 meV/Te more stable than and the {\epsilon} phase shows
comparable stability with the most stable monolayer {\gamma} phase. The
energetic difference between the {\zeta} and {\alpha} phases reduces with
respect to the increased layer thickness and vanishes at the four-layer
(12-sublayer) thickness, while this thickness increases under change doping.
Both {\epsilon} and {\zeta} phases are metallic chains and layers,
respectively. The {\zeta} phase, with very strong interlayer coupling, shows
quantum well states in its layer-dependent bandstructures. These results
provide significantly insight into the understanding of polytypism in Te
few-layers and may boost tremendous studies on properties of various few-layer
phases.

9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con