Title
Spin qudit tomography and state reconstruction error
Date Issued
01 December 2021
Access level
open access
Resource Type
journal article
Author(s)
University of Colorado
Publisher(s)
American Physical Society
Abstract
We consider the task of performing quantum state tomography on a d-level spin qudit, using only measurements of spin projection onto different quantization axes. After introducing a basis of operators closely related to the spherical harmonics, which obey the rotational symmetries of spin qudits, we map our quantum tomography task onto the classical problem of signal recovery on the sphere. We then provide algorithms with O(rd3) serial runtime, parallelizable down to O(rd2) for: (i) computing a priori upper bounds on the expected error with which spin projection measurements along r given axes can reconstruct an unknown qudit state, and (ii) estimating a posteriori the statistical error in a reconstructed state. Our algorithms motivate a simple randomized tomography protocol for which we find that using more measurement axes can yield substantial benefits that plateau after r≈3d.
Volume
104
Issue
6
Language
English
OCDE Knowledge area
Física de partículas, Campos de la Física
Física y Astronomía
Scopus EID
2-s2.0-85121864947
Source
Physical Review A
ISSN of the container
24699926
Sponsor(s)
We thank A. M. Polloreno and J. T. Young for helpful feedback. This work is supported by the DARPA DRINQs Grant, the ARO single investigator Award No. W911NF-19-1-0210, AFOSR Grant No. FA9550-19-1-0275, NSF Grant No. PHY-1820885, NSF Grant No. PHY-1734006 (JILA-PFC), and by NIST.
Sources of information:
Directorio de Producción Científica
Scopus