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Bibliographic Details
Main Authors: Allam, Jawad, Matzkin, Alex
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2410.20450
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author Allam, Jawad
Matzkin, Alex
author_facet Allam, Jawad
Matzkin, Alex
contents The evolution of the quantum state of a system upon measurement results in state update. In this work, we investigate the characterization of updated states of multi-partite entangled qubit states with non-destructive weak measurements, involving weakly coupling a pointer to each qubit in a relativistic context. As is well-known, the updated state at intermediate times is frame-dependent, and outcome randomness intrinsic to projective measurements prevents any information to be acquired on the updated state. Here we will see that when weak measurements are implemented there is instead an interplay between randomness and interference, depending on the number of qubits, so as to maintain consistency between descriptions in arbitrary reference frames. Analytical results are given for a small or infinite number of qubits, while for a finite number of qubits we will resort to Monte-Carlo sampling in order to simulate numerically the results of weak measurements. As a by-product, we show how a single-shot measurement of the pointers positions allows to make quantitative predictions on the outcomes that can be obtained for any observable measured on a distant qubit of the multi-partite state.
format Preprint
id arxiv_https___arxiv_org_abs_2410_20450
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Characterizing entangled state update in different reference frames with weak measurements
Allam, Jawad
Matzkin, Alex
Quantum Physics
The evolution of the quantum state of a system upon measurement results in state update. In this work, we investigate the characterization of updated states of multi-partite entangled qubit states with non-destructive weak measurements, involving weakly coupling a pointer to each qubit in a relativistic context. As is well-known, the updated state at intermediate times is frame-dependent, and outcome randomness intrinsic to projective measurements prevents any information to be acquired on the updated state. Here we will see that when weak measurements are implemented there is instead an interplay between randomness and interference, depending on the number of qubits, so as to maintain consistency between descriptions in arbitrary reference frames. Analytical results are given for a small or infinite number of qubits, while for a finite number of qubits we will resort to Monte-Carlo sampling in order to simulate numerically the results of weak measurements. As a by-product, we show how a single-shot measurement of the pointers positions allows to make quantitative predictions on the outcomes that can be obtained for any observable measured on a distant qubit of the multi-partite state.
title Characterizing entangled state update in different reference frames with weak measurements
topic Quantum Physics
url https://arxiv.org/abs/2410.20450