Loop State-preparation-and-measurement tomography of a two-qubit system

We experimentally demonstrate that loop state-preparation-and-measurement (SPAM) tomography is capable of detecting correlated errors in a two-qubit system. We prepare photon pairs in a state that approximates a Werner state, which may or may not be entangled. By performing measurements with multipl...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2018-07
Main Authors: Feldman, M E, Juul, G K, Van Enk, S J, Beck, M
Format: Article
Language:English
Subjects:
Correlation analysis
Performance degradation
Quantum phenomena
Quantum theory
Qubits (quantum computing)
Tomography
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We experimentally demonstrate that loop state-preparation-and-measurement (SPAM) tomography is capable of detecting correlated errors in a two-qubit system. We prepare photon pairs in a state that approximates a Werner state, which may or may not be entangled. By performing measurements with multiple different detector settings we are able to detect correlated errors between two single-qubit measurements performed in different locations. No assumptions are made concerning either the state preparations or the measurements, other than that the dimensions of the states and the positive-operator-valued measures describing the detectors are known. The only other needed information is experimentally measured expectation values, which are analyzed for self-consistency. This demonstrates that loop SPAM tomography is a useful technique for detecting errors that would degrade the performance of multiple-qubit quantum information processors.
ISSN:2331-8422
DOI:10.48550/arxiv.1806.06697