scholarly journals Quantum Advantages of Communication Complexity from Bell Nonlocality

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 744
Author(s):  
Zhih-Ahn Jia ◽  
Lu Wei ◽  
Yu-Chun Wu ◽  
Guang-Can Guo

Communication games are crucial tools for investigating the limitations of physical theories. The communication complexity (CC) problem is a typical example, for which several distributed parties attempt to jointly calculate a given function with limited classical communications. In this work, we present a method to construct CC problems from Bell tests in a graph-theoretic way. Starting from an experimental compatibility graph and the corresponding Bell test function, a target function that encodes the information of each edge can be constructed; then, using this target function, we can construct a CC function, and by pre-sharing entangled states, its success probability exceeds that of the arbitrary classical strategy. The non-signaling protocol based on the Popescu–Rohrlich box is also discussed, and the success probability in this case reaches one.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. K. Pan

AbstractAn ontological model of an operational theory is considered to be universally noncontextual if both preparation and measurement noncontextuality assumptions are satisfied in that model. In this report, we first generalize the logical proofs of quantum preparation and measurement contextuality for qubit system for any odd number of preparations and measurements. Based on the logical proof, we derive testable universally non-contextual inequalities violated by quantum theory. We then propose a class of two-party communication games and show that the average success probability of winning such games is solely linked to suitable Bell expression whose local bound is greater than universal non-contextual bound. Thus, for a given state, even if quantum theory does not exhibit non-locality, it may still reveal non-classicality by violating the universal non-contextual bound. Further, we consider a different communication game to demonstrate that for a given choices of observables in quantum theory, even if there is no logical proof of preparation and measurement contextuality exist, the universal quantum contextuality can be revealed through that communication game. Such a game thus test a weaker form of universal non-contextuality with minimal assumption.



2016 ◽  
Vol 113 (12) ◽  
pp. 3191-3196 ◽  
Author(s):  
Harry Buhrman ◽  
Łukasz Czekaj ◽  
Andrzej Grudka ◽  
Michał Horodecki ◽  
Paweł Horodecki ◽  
...  

We obtain a general connection between a large quantum advantage in communication complexity and Bell nonlocality. We show that given any protocol offering a sufficiently large quantum advantage in communication complexity, there exists a way of obtaining measurement statistics that violate some Bell inequality. Our main tool is port-based teleportation. If the gap between quantum and classical communication complexity can grow arbitrarily large, the ratio of the quantum value to the classical value of the Bell quantity becomes unbounded with the increase in the number of inputs and outputs.



2013 ◽  
Vol 13 (3&4) ◽  
pp. 334-360
Author(s):  
Jop Briet ◽  
Harry Buhrman ◽  
Troy Lee ◽  
Thomas Vidick

We study multipartite entanglement in the context of XOR games. In particular, we study the ratio of the entangled and classical \emph{biases}, which measure the maximum advantage of a quantum or classical strategy over a uniformly random strategy. For the case of two-player XOR games, Tsirelson proved that this ratio is upper bounded by the celebrated Grothendieck constant. In contrast, \PG proved the existence of entangled states that give quantum players an unbounded advantage over classical players in a three-player XOR game. We show that the multipartite entangled states that are most often seen in today's literature can only lead to a bias that is a constant factor larger than the classical bias. These states include GHZ states, any state local-unitarily equivalent to combinations of GHZ and maximally entangled states shared between different subsets of the players (e.g., stabilizer states), as well as generalizations of GHZ states of the form $\sum_i \alpha_i \ket{i}\cdots\ket{i}$ for arbitrary amplitudes $\alpha_i$. Our results have the following surprising consequence: \emph{classical} three-player XOR games do not follow an XOR parallel repetition theorem, even a very weak one. Besides this, we discuss implications of our results for communication complexity and hardness of approximation. Our proofs are based on novel applications of extensions of Grothendieck's inequality, due to Blei and Tonge, and Carne, generalizing Tsirelson's use of Grothendieck's inequality to bound the bias of two-player XOR games.



2020 ◽  
Vol 5 (1) ◽  
pp. 61
Author(s):  
Vadlan Febrian ◽  
Muhamad Rizki Ramadhan ◽  
Muhammad Faisal ◽  
Aries Saifudin

In this employee payroll application, if there is an error program there will be a loss for employees and the company. Losses for employees, if this application program error occurs then the salary reduction will experience delays due to the difficulty in the process of calculating employee salaries and employees will be late in receiving salaries. Losses for the company, if there is an error program in this application, the company will suffer losses if the employee wants a salary reduction quickly but the company cannot calculate quickly and accurately. In solving this problem, the authors use the black box testing method. Black box testing method is a test that sees the results of execution through test data and ensures the function of the software. Black box testing method has several testing techniques, namely Sample Testing, Boundary Value Analysis, Equivalence Partitions and others. From the testing techniques that have been mentioned, we use the Equivalence Partitions testing technique. Equivalence Partitions are tests that refer to data entry on the employee payroll application form, input will be tested and then put together based on the test function, both valid and invalid values. The expected results of this test are a payroll system for employees who are computerized, have standard rules in the process of developing the program so that it is easy to develop and maintain, and can minimize errors in processing salary calculations for employees.



In the article, the author considers the problems of complex algorithmization and systematization of approaches to optimizing the work plans of construction organizations (calendar plans) using various modern tools, including, for example, evolutionary algorithms for "conscious" enumeration of options for solving a target function from an array of possible constraints for a given nomenclature. Various typical schemes for modeling the processes of distribution of labor resources between objects of the production program are given, taking into account the array of source data. This data includes the possibility of using the material and technical supply base (delivery, storage, packaging) as a temporary container for placing the labor resource in case of released capacity, quantitative and qualification composition of the initial labor resource, the properties of the construction organization as a counterparty in the contract system with the customer of construction and installation works etc. A conceptual algorithm is formed that is the basis of the software package for operational harmonization of the production program ( work plans) in accordance with the loading of production units, the released capacities of labor resources and other conditions stipulated by the model. The application of the proposed algorithm is most convenient for a set of objects, which determines the relevance of its implementation in optimization models when planning production programs of building organizations that contain several objects distributed over a time scale.



2016 ◽  
Vol 22 (98) ◽  
pp. 378-383
Author(s):  
Andrei O. Levchenko ◽  
◽  
Yurii A., Maksymenko ◽  
Yurii I. Ryndin ◽  
Igor A. Shumkov ◽  
...  
Keyword(s):  


2007 ◽  
Author(s):  
T. Lee ◽  
A. Shraibman




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