{"title":"Instantaneous measurement can isolate the information","authors":"Iman Sargolzahi","doi":"10.1007/s11128-025-04708-7","DOIUrl":null,"url":null,"abstract":"<div><p>Consider a one-dimensional spin chain, from spin 1 to spin <i>N</i>, such that each spin interacts with its nearest neighbors. Performing a local operation (measurement) on spin <i>N</i>, we expect from the Lieb–Robinson velocity that, in general, the effect of this measurement achieves spin 1 after some while. But, in this paper, we show that if (a) the measurement on spin <i>N</i> is performed instantaneously and (b) the initial state of the spin chain is chosen appropriately, then the effect of the measurement on spin <i>N</i> never achieves spin 1. In other words, performing or not performing an instantaneous measurement on spin <i>N</i> at <span>\\(t=0\\)</span> does not alter the reduced dynamics of spin 1 for all the times <span>\\(t\\ge 0\\)</span>. We can interpret this as the following: The information of performing an instantaneous measurement on spin <i>N</i> is isolated such that it cannot achieve spin 1.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"24 3","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Quantum Information Processing","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s11128-025-04708-7","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHYSICS, MATHEMATICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Consider a one-dimensional spin chain, from spin 1 to spin N, such that each spin interacts with its nearest neighbors. Performing a local operation (measurement) on spin N, we expect from the Lieb–Robinson velocity that, in general, the effect of this measurement achieves spin 1 after some while. But, in this paper, we show that if (a) the measurement on spin N is performed instantaneously and (b) the initial state of the spin chain is chosen appropriately, then the effect of the measurement on spin N never achieves spin 1. In other words, performing or not performing an instantaneous measurement on spin N at \(t=0\) does not alter the reduced dynamics of spin 1 for all the times \(t\ge 0\). We can interpret this as the following: The information of performing an instantaneous measurement on spin N is isolated such that it cannot achieve spin 1.
期刊介绍：
Quantum Information Processing is a high-impact, international journal publishing cutting-edge experimental and theoretical research in all areas of Quantum Information Science. Topics of interest include quantum cryptography and communications, entanglement and discord, quantum algorithms, quantum error correction and fault tolerance, quantum computer science, quantum imaging and sensing, and experimental platforms for quantum information. Quantum Information Processing supports and inspires research by providing a comprehensive peer review process, and broadcasting high quality results in a range of formats. These include original papers, letters, broadly focused perspectives, comprehensive review articles, book reviews, and special topical issues. The journal is particularly interested in papers detailing and demonstrating quantum information protocols for cryptography, communications, computation, and sensing.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
