Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Noisy Quantum Computation Modeled by Quantum Walk: Universality without
  Ancillas   The universal quantum computation model based on quantum walk by Childs has
opened the door for a new way of studying the limitations and advantages of
quantum computation, as well as for its intermediate-term simulation. In recent
years, the growing interest in noisy intermediate-scale quantum computers
(NISQ) has lead to intense efforts being directed at understanding the
computational advantages of open quantum systems. In this work, we extend the
quantum walk model to open noisy systems in order to provide such a tool for
the study of NISQ computers. Our method does not use explicit purification, and
allows to ignore the environment degrees of freedom and obtain a much more
efficient implementation (linear rather than exponential in the runtime), which
employs no ancillas hence provides direct access to the entanglement properties
of the system. In our scheme, the quantum walk amplitudes represent elements of
the density matrix rather than the wavefunction of a pure state. Despite the
non-trivial manifestation of the normalization requirement in this setting, we
model the application of general unitary gates and nonunitary channels, with an
explicit implementation protocol for channels that are commonly used in noise
models.

12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess