Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Improved Gradual Resistive Switching Range and 1000x On/Off Ratio in
  HfOx RRAM Achieved with a $Ge_2Sb_2Te_5$ Thermal Barrier
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th