Distributed Shor's algorithm
(pp0027-0044)
Ligang Xiao, Daowen Qiu,
Le Luo and Paulo Mateus
doi:
https://doi.org/10.26421/QIC23.1-2-3
Abstracts:
Shor's
algorithm is one of the most important quantum algorithm proposed by
Peter
Shor [Proceedings of the 35th Annual
Symposium on Foundations of Computer Science, 1994, pp. 124--134].
Shor's
algorithm can factor a large integer with certain probability and costs
polynomial time in the length of the input integer. The key step of
Shor's
algorithm is the order-finding algorithm, the quantum part of which is
to estimate $s/r$,
where $r$
is the ``order" and $s$
is some natural number that less than
$r$. {{Shor's
algorithm requires lots of
qubits
and a deep circuit depth, which is
unaffordable
for current physical devices.}} In this paper, to reduce the number of
qubits
required and circuit depth, we propose a quantum-classical hybrid
distributed order-finding algorithm for
Shor's
algorithm, which combines the advantages of both quantum processing and
classical processing. {{ In our distributed order-finding algorithm, we
use two quantum computers with the ability of quantum
teleportation
separately to estimate partial bits of
$s/r$.}}
The measuring results will be processed through a classical algorithm to
ensure the accuracy of the results. Compared with the traditional
Shor's
algorithm that uses multiple control
qubits,
our algorithm reduces nearly $L/2$
qubits
for factoring an $L$-bit
integer and reduces the circuit depth of each computer.
Key Words:
Shor's algorithm, distributed
Shor's algorithm, quantum-classcial hybrid, quantum teleportation,
circuit depth |