Entangling and disentangling in Grover's search algorithm

PAN, Minghua, Daowen QIU, Paulo MATEUS a Jozef GRUSKA. Entangling and disentangling in Grover's search algorithm. Theoretical Computer Science. Amsterdam: Elsevier, 2019, roč. 773, 14 June 2019, s. 138-152. ISSN 0304-3975. Dostupné z: https://dx.doi.org/10.1016/j.tcs.2018.10.001.

Základní údaje

• Originální název: Entangling and disentangling in Grover's search algorithm
• Autoři: PAN, Minghua, Daowen QIU, Paulo MATEUS a Jozef GRUSKA (703 Slovensko, domácí).
• Vydání: Theoretical Computer Science, Amsterdam, Elsevier, 2019, 0304-3975.

Další údaje

• Originální jazyk: angličtina
• Typ výsledku: Článek v odborném periodiku
• Obor: 10201 Computer sciences, information science, bioinformatics
• Stát vydavatele: Německo
• Utajení: není předmětem státního či obchodního tajemství
• WWW: URL
• Impakt faktor: Impact factor: 0.747
• Kód RIV: RIV/00216224:14330/19:00113867
• Organizační jednotka: Fakulta informatiky
• Doi: http://dx.doi.org/10.1016/j.tcs.2018.10.001
• UT WoS: 000469907500009
• Klíčová slova anglicky: Entanglement dynamics; Grover's search algorithm; Geometric measure of entanglement
• Příznaky: Mezinárodní význam, Recenzováno

Anotace

Entanglement is believed to be crucial in making quantum algorithms more powerful than their classical counterparts for certain computational tasks. In Grover's search algorithm, the Grover's operator iteration G can be decomposed into two basic operators, i.e., G = RO, where O is so called the Oracle operator and R is the Reflection operator. To probe the production/depletion of entanglement from basic operator level, we investigate the roles the Oracle and the Reflection operators play in the entanglement dynamics during Grover's search algorithm application. Using geometric measure of entanglement (GME), we show that the Oracle operator is an entangling operator which almost always produces (increases) entanglement while the Reflection operator is a disentangling operator which mainly depletes (decreases) entanglement. We explicitly demonstrate that there exists a turning point during the Grover's iteration application with the following properties. Before that turning point, the entanglement is almost always increased when the Oracle operator is applied, and the effect of the Reflection operator on the level of entanglement can be almost ignored. However, after the turning point, both the Oracle and the Reflection operators play important roles to the entanglement, more exactly, the Reflection operator significantly decreases entanglement while the Oracle operator increases entanglement. All these results are carefully demonstrated.