Demonstration of Shor’s factoring algorithm for N = 21 on IBM quantum processors

Date
2021-08-16
Journal Title
Journal ISSN
Volume Title
Publisher
Nature
Abstract
We report a proof-of-concept demonstration of a quantum order-finding algorithm for factoring the integer 21. Our demonstration involves the use of a compiled version of the quantum phase estimation routine, and builds upon a previous demonstration. We go beyond this work by using a configuration of approximate Toffoli gates with residual phase shifts, which preserves the functional correctness and allows us to achieve a complete factoring of N=21 . We implemented the algorithm on IBM quantum processors using only five qubits and successfully verified the presence of entanglement between the control and work register qubits, which is a necessary condition for the algorithm’s speedup in general. The techniques we employ may be useful in carrying out Shor’s algorithm for larger integers, or other algorithms in systems with a limited number of noisy qubits.
Description
CITATION: Skosana, U. & Tame, M. 2021. Demonstration of Shor's factoring algorithm for N = 21 on IBM quantum processors. Scientific Reports, 11:16599, doi:10.1038/s41598-021-95973-w.
The original publication is available at https://www.nature.com
Keywords
Algorithms, Quantum theory, Quantum Physics, Shor’s algorithm, IBM quantum processors
Citation
Skosana, U. & Tame, M. 2021. Demonstration of Shor's factoring algorithm for N = 21 on IBM quantum processors. Scientific Reports, 11:16599, doi:10.1038/s41598-021-95973-w.