Reducing backaction when measuring temporal correlations in quantum systems

Dynamic correlations of quantum observables are challenging to measure due to measurement backaction incurred at early times. Recent work [P. Uhrich et al., Phys. Rev. A, 96:022127 (2017)] has shown that ancilla-based noninvasive measurements are able to reduce this backaction, allowing for dynamic correlations of single-site spin observables to be measured. We generalise this result to correlations of arbitrary spin observables and extend the measurement protocol to simultaneous noninvasive measurements which allow for real and imaginary parts of correlations to be extracted from a single set of measurements. We use positive operator-valued measures to analyse the dynamics generated by the ancilla-based measurements. Using this framework we prove that special observables exist for which measurement backaction is of no concern, so that dynamic correlations of these can be obtained without making use of ancillas.Comment: 13 page

Probing unitary two-time correlations in a neutral atom quantum simulator

Measuring unitarily-evolved quantum mechanical two-time correlations is challenging in general. In a recent paper [P.~Uhrich {\em et al.}, Phys.\ Rev.~A {\bf 96}, 022127 (2017)], a considerable simplification of this task has been pointed out to occur in spin-$1/2$ lattice models, bringing such measurements into reach of state-of-the-art or near-future quantum simulators of such models. Here we discuss the challenges of an experimental implementation of measurement schemes of two-time correlations in quantum gas microscopes or microtrap arrays. We propose a modified measurement protocol that mitigates these challenges, and we rigorously estimate the accuracy of the protocols by means of Lieb-Robinson bounds. On the basis of these bounds we identify a parameter regime in which the proposed protocols allow for accurate measurements of the desired two-time correlations.Comment: 15 pages, 2 figure

#Rest in Digital Peace: Examining Attachment Dimensions\u27 Relationship to Grief Messages on Facebook

Grief is a natural reaction to loss that can include behaviors and thoughts that are emotional, physical, and spiritual (DeSpelder & Strickland, 2015). With the rise of social media, grief is now performed in a different and more public manner. The current literature has established the connection between how one grieves and their attachment dimension of either attachment anxiety or attachment avoidance (Bowlby, 1980; Schenck, Eberle, & Rings, 2016; Waskowic & Chartier, 2003; Worden, 1983). Attachment dimensions have also been correlated with social media usage, primarily the use of Facebook (Hart, Nalling, Bizer, & Collins, 2015; Lin, 2015). Findings from a series of Pearson correlations (n = 257) indicate a relationship between attachment anxiety and the likelihood to post a status update following the death of a friend and posting a status update following the death of a celebrity. Additionally, results indicate a relationship between attachment anxiety and the likelihood to post on the deceased’s wall following the death of a community member. In the case of attachment avoidance, a relationship is found with posting a status update following the death of a family member and an acquaintance. A series of Kruskal-Wallis tests found that those with preoccupied attachment are more likely than those with secure attachment to post on a deceased friend’s wall, post on a deceased community member’s wall, direct message deceased family members, and direct message a deceased friend

Hallie Uhrich Honors Portfolio

Hallie Uhrich\u27s honors portfolio captured in May 2018

A Case Study of the Economic Impact of the 3M Company of the Brookings Community

Communities can pursue a program of industria1 deve1opment by attracting new industry and/or encountering the expansion of existing industry. Shaffer felt that a community should consider two sets of questions before actively assisting additional industry to locate within the community. The first set of questions pertains to the feasibility of the business. The second set of questions involves determining the economic impact of the business on the community.” The first set of questions is not within the scope of this study; however, the second set will be considered and data. Shaffer felt that a community should consider two sets of questions before actively assisting additional industry to locate within the community. The first set of questions pertains to the feasibility of the business. The second set of questions involves determining the economic impact of the business on the community.” The first set of questions is not within the scope of this study; however, the second set will be considered. Overall, South Dakota experienced a decline of 2.2 percent in its population during the 1960-70 decade. During the same time frame the urban area of Brookings experienced a population increase of more than twice the national average of 26.6 percent. The projected population for urban Brookings is 20,900 by 1985, a 46 percent increase from the 1970 census count of 14,300. This growth will be induced and supported largely by an expansion of existing industry (currently Brookings is the home of 26 manufacturers and processors) and/or the introduction of additional industry into the community. This study is concerned with estimating the annual economic impact of this industry on the economy of the Brookings Community. Due to expansion plans and possible addition of more new industry to the economic base, Brookings is confronted with making the determination of what costs will be incurred and what benefits can reasonably be expected from the added industry. Estimates of costs and benefits obtained comprise vital economic data needed to determine whether or not this particular addition to the economy has been beneficial and whether or not inducements are warranted for future additions to the economy. The general objective of this study was to implement a model which measures changes in the Brookings Community\u27s private and public sectors induced by the addition of Minnesota Mining & Manufacturing Co. to the local economy and to estimate the annua1 economic impact. Specifically, the objectives were as follows: 1) To develop an economic profile of employees. 2) To determine the net gain (loss} to the community\u27s private sector

Economic Espionage Act--Reverse Engineering and the Intellectual Property Public Policy, The

The publicity surrounding[...] incidents of industrial espionage resulted in a push for federal protections. In response to this pressure from U.S. industries, Congress passed the Economic Espionage Act of 1996 ( EEA ). The EEA protects trade secrets through the use of federal criminal sanctions. The EEA\u27s provisions are introduced in Part I. Trade secrets are a form of intellectual property. Therefore, a basic understanding of intellectual property law is important to an analysis of the EEA. Part II of this Article provides an overview of the various forms of intellectual property. To be effective, the EEA must complement existing intellectual property jurisprudence. Yet, on its face the EEA prohibits practices that are otherwise lawful as part of a reverse engineering program. Part II of this Article also describes reverse engineering and examines its acceptance in each area of intellectual property law. Understanding the EEA in terms of the other forms of intellectual property protection and the practice of reverse engineering raises some concerns over the prudence of vigorous EEA enforcement. A strict reading of the EEA may prohibit reverse engineering. Since reverse engineering plays a significant role in the exploitation of knowledge committed to the public domain through the grant of patents and copyrights, prohibiting reverse engineering may stifle the drive to study and improve upon the existing knowledge base. Part III of this Article examines these concerns. The increasing importance of intellectual property in the world economy has created a trend toward criminalization of infringement. In addition to the acts covered by the EEA, some international agreements require criminal sanctions for infringement of various rights, certain acts of copyright infringement carry criminal penalties, and Congress is currently considering the Collections of Information Antipiracy Act. While these laws are designed to protect intellectual property, the inclusion of criminal sanctions means that they must be analyzed in light of criminal law theories such as notice, vagueness, and leniency. As this trend continues, and prosecutions under these new laws become more frequent, it will be important for criminal practitioners to have a firm grasp of intellectual property concepts and for intellectual property attorneys to understand the importance of criminal law. Finally, it is important for Congress to consider such criminal law issues when enacting new intellectual property legislation. A discussion of these issues with respect to the EEA provides a framework for developing this discussion with respect to other intellectual property laws. To assist in determining the legitimacy of these concerns, Part I also examines the legislative history of the EEA to ascertain congressional intent with respect to the identified problems. Based upon the issues raised in Part III, Part IV proposes a solution to address these concerns while maintaining the effectiveness of the EEA in fulfilling its intended purpose. Specifically, the Article proposes amending the EEA to explicitly allow reverse engineering and to limit its application to espionage activities similar to those Congress had in mind when drafting the Act