English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study sequential state discrimination measurements performed on the samequbit by subsequent observers. Specifically, we focus on the case when theobservers perform a kind of a minimum-error type state discriminatingmeasurement where the goal of the observers is to maximize their jointprobability of successfully guessing the state that the qubit was initiallyprepared in. We call this the joint best guess strategy. In this scheme, Aliceprepares a qubit in one of two possible states. The qubit is first sent to Bob,who measures it, and then on to Charlie, and so on to altogether N consecutivereceivers who all perform measurements on it. The goal for all observers is todetermine which state Alice sent. In the joint best guess strategy, every timea system is received the observer is required to make a guess, aided by themeasurement, about its state. The price to pay for this requirement is thaterrors must be permitted, the guess can be correct or in error. There is anonzero probability for all the receivers to successfully identify theinitially prepared state, and we maximize this joint probability of success.This work is a step toward developing a theory of nondestructive sequentialquantum measurements and could be useful in multiparty quantum communicationschemes based on communicating with single qubits, particularly in schemesemploying continuous variable states. It also represents a case wheresubsequent observers can probabilistically and optimally get around both thecollapse postulate and the no-broadcasting theorem.

Sequential measurements on qubits by multiple observers: Joint best guess strategy