Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singular continuous Cantor spectrum for magnetic quantum walks   In this note, we consider a physical system given by a two-dimensional
quantum walk in an external magnetic field. In this setup, we show that both
the topological structure as well as its type depend sensitively on the value
of the magnetic flux $\Phi$: while for $\Phi/(2{\pi})$ rational the spectrum is
known to consist of bands, we show that for $\Phi/(2{\pi})$ irrational the
spectrum is a zero-measure Cantor set and the spectral measures have no pure
point part.

21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat