Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photogalvanic effects in HgTe quantum wells   We report on the observation of the terahertz radiation induced circular
(CPGE) and linear (LPGE) photogalvanic effects in HgTe quantum wells. The
current response is well described by the phenomenological theory of CPGE and
LPGE.

36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph