Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Chiral Anomaly and Ultrahigh Mobility in Crystalline HfTe5   HfTe5 is predicted to be a promising platform for studying topological
phases. Here through an electrical transport study, we present the first
observation of chiral anomaly and ultrahigh mobility in HfTe5 crystals.
Negative magneto-resistivity in HfTe5 is observed when the external magnetic
and electrical fields are parallel (B//E) and quickly disappears once B
deviates from the direction of E. Quantitative fitting further confirms the
chiral anomaly as the underlying physics. Moreover, by analyzing the
conductivity tensors of longitudinal and Hall traces, ultrahigh mobility and
ultralow carrier density are revealed in HfTe5, which paves the way for
potential electronic applications.

13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
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
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org