Universität zu Köln

Hou, Zhibo, Tang, Jun-Feng, Shang, Jiangwei, Zhu, Huangjun, Li, Jian, Yuan, Yuan, Wu, Kang-Da, Xiang, Guo-Yong, Li, Chuan-Feng and Guo, Guang-Can (2018). Deterministic realization of collective measurements via photonic quantum walks. Nat. Commun., 9. LONDON: NATURE PUBLISHING GROUP. ISSN 2041-1723

Full text not available from this repository.

Abstract

Collective measurements on identically prepared quantum systems can extract more information than local measurements, thereby enhancing information-processing efficiency. Although this nonclassical phenomenon has been known for two decades, it has remained a challenging task to demonstrate the advantage of collective measurements in experiments. Here, we introduce a general recipe for performing deterministic collective measurements on two identically prepared qubits based on quantum walks. Using photonic quantum walks, we realize experimentally an optimized collective measurement with fidelity 0.9946 without post selection. As an application, we achieve the highest tomographic efficiency in qubit state tomography to date. Our work offers an effective recipe for beating the precision limit of local measurements in quantum state tomography and metrology. In addition, our study opens an avenue for harvesting the power of collective measurements in quantum information-processing and for exploring the intriguing physics behind this power.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Hou, Zhibo UNSPECIFIED UNSPECIFIED UNSPECIFIED Tang, Jun-Feng UNSPECIFIED UNSPECIFIED UNSPECIFIED Shang, Jiangwei UNSPECIFIED UNSPECIFIED UNSPECIFIED Zhu, Huangjun UNSPECIFIED UNSPECIFIED UNSPECIFIED Li, Jian UNSPECIFIED UNSPECIFIED UNSPECIFIED Yuan, Yuan UNSPECIFIED UNSPECIFIED UNSPECIFIED Wu, Kang-Da UNSPECIFIED UNSPECIFIED UNSPECIFIED Xiang, Guo-Yong UNSPECIFIED UNSPECIFIED UNSPECIFIED Li, Chuan-Feng UNSPECIFIED UNSPECIFIED UNSPECIFIED Guo, Guang-Can UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-189412
DOI:	10.1038/s41467-018-03849-x
Journal or Publication Title:	Nat. Commun.
Volume:	9
Date:	2018
Publisher:	NATURE PUBLISHING GROUP
Place of Publication:	LONDON
ISSN:	2041-1723
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language STATE TOMOGRAPHY; ENTANGLEMENT; METROLOGY; INFORMATION; LIMIT Multiple languages Multidisciplinary Sciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/18941