Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Approximate quantum error correction for correlated noise   Most of the research done on quantum error correction studies an error model
in which each qubit is affected by noise, independently of the other qubits. In
this paper we study a different noise model -- one in which the noise may be
correlated with the qubits it acts upon.
  We show both positive and negative results. On the one hand, we show
controlled-X errors cannot be perfectly corrected, yet can be approximately
corrected with sub-constant approximation error. On the other hand, we show
that no non-trivial quantum error correcting code can approximately correct
controlled phase error with sub-constant approximation error.

31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org