Measurement sharpness and disturbance tradeoff

Fuente: arXiv
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Main Authors: Saberian, Nayere, Akhtarshenas, Seyed Javad, Shahbeigi, Fereshte
Format: Preprint
Published: 2023
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author Saberian, Nayere
Akhtarshenas, Seyed Javad
Shahbeigi, Fereshte
author_facet Saberian, Nayere
Akhtarshenas, Seyed Javad
Shahbeigi, Fereshte
contents Obtaining information from a quantum system through a measurement typically disturbs its state. The postmeasurement states for a given measurement, however, are not unique and highly rely on the chosen measurement model, complicating the puzzle of information-disturbance. Two distinct questions are then in order. Firstly, what is the minimum disturbance a measurement may induce? Secondly, when a fixed disturbance occurs, how informative is the possible measurement in the best-case scenario? Here, we propose various approaches to tackle these questions and provide explicit solutions for the set of unbiased binary qubit measurements and postmeasurement state spaces that are equivalent to the image of a unital qubit channel. In particular, we show there are different tradeoff relations between the sharpness of this measurement and the average fidelity of the premeasurement and postmeasurement state spaces as well as the sharpness and quantum resources preserved in the postmeasurement states in terms of coherence and discord-like correlation once the measurement is applied locally.
format Preprint
id arxiv_https___arxiv_org_abs_2308_04133
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Measurement sharpness and disturbance tradeoff
Saberian, Nayere
Akhtarshenas, Seyed Javad
Shahbeigi, Fereshte
Quantum Physics
Obtaining information from a quantum system through a measurement typically disturbs its state. The postmeasurement states for a given measurement, however, are not unique and highly rely on the chosen measurement model, complicating the puzzle of information-disturbance. Two distinct questions are then in order. Firstly, what is the minimum disturbance a measurement may induce? Secondly, when a fixed disturbance occurs, how informative is the possible measurement in the best-case scenario? Here, we propose various approaches to tackle these questions and provide explicit solutions for the set of unbiased binary qubit measurements and postmeasurement state spaces that are equivalent to the image of a unital qubit channel. In particular, we show there are different tradeoff relations between the sharpness of this measurement and the average fidelity of the premeasurement and postmeasurement state spaces as well as the sharpness and quantum resources preserved in the postmeasurement states in terms of coherence and discord-like correlation once the measurement is applied locally.
title Measurement sharpness and disturbance tradeoff
topic Quantum Physics
url https://arxiv.org/abs/2308.04133