Saved in:
Bibliographic Details
Main Authors: Guo, Yuxuan, Ashida, Yuto
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2411.17020
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910727953973248
author Guo, Yuxuan
Ashida, Yuto
author_facet Guo, Yuxuan
Ashida, Yuto
contents Preparing highly entangled quantum states is a key challenge in quantum metrology and quantum information science. Measurements, especially those of global observables, offer a simple and efficient way to generate entanglement between subsystems when they are measured as a whole. We introduce a log-depth protocol leveraging quantum phase estimation to measure a global observable, such as total magnetization and momentum. We demonstrate its capability to prepare towers of structured excited states that are useful in quantum metrology; examples include quantum many-body scars in various models, including the Affleck-Kennedy-Lieb-Tasaki (AKLT) model, the constrained domain-wall model, and the spin-$\frac{1}{2}$ and spin-$1$ XX chains. The same method is also applicable to preparing the Dicke states of high weight. In addition, we propose a protocol for momentum measurement that avoids disturbing the system, facilitating the preparation of states beyond the above construction, such as the Arovas $A$ state of the AKLT Hamiltonian. Our results expand the utility of measurement-based approaches to accessing highly entangled states in quantum many-body systems.
format Preprint
id arxiv_https___arxiv_org_abs_2411_17020
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Tower of Structured Excited States from Measurements
Guo, Yuxuan
Ashida, Yuto
Quantum Physics
Other Condensed Matter
Preparing highly entangled quantum states is a key challenge in quantum metrology and quantum information science. Measurements, especially those of global observables, offer a simple and efficient way to generate entanglement between subsystems when they are measured as a whole. We introduce a log-depth protocol leveraging quantum phase estimation to measure a global observable, such as total magnetization and momentum. We demonstrate its capability to prepare towers of structured excited states that are useful in quantum metrology; examples include quantum many-body scars in various models, including the Affleck-Kennedy-Lieb-Tasaki (AKLT) model, the constrained domain-wall model, and the spin-$\frac{1}{2}$ and spin-$1$ XX chains. The same method is also applicable to preparing the Dicke states of high weight. In addition, we propose a protocol for momentum measurement that avoids disturbing the system, facilitating the preparation of states beyond the above construction, such as the Arovas $A$ state of the AKLT Hamiltonian. Our results expand the utility of measurement-based approaches to accessing highly entangled states in quantum many-body systems.
title Tower of Structured Excited States from Measurements
topic Quantum Physics
Other Condensed Matter
url https://arxiv.org/abs/2411.17020