[ANGLÈS] A theoretical base on quantum physics, quantum computing and mathematical models is the starting point for the development of the applications collection Quantum Graph Tool. It consists on four applications for the iOS operating system related to quantum computing and graph theory. To be more precise, the two main applications are interactive simulators of Grover’s quantum algorithm (to search in ordered lists) and Shor’s quantum algorithm (to factorize integer numbers). These applications aim to divulge quantum computing using mobile devices (iPad) and, in addition, they are tools to study new computing methods based on quantum mechanics’ properties. With the same objective, besides the applications, cumulative computing is introduced as a new computing method to solve problems in graph theory.
[ANGLÈS] A theoretical base on quantum physics, quantum computing and mathematical models is the starting point for the development of the applications collection Quantum Graph Tool. It consists on four applications for the iOS operating system related to quantum computing and graph theory. To be more precise, the two main applications are interactive simulators of Grover’s quantum algorithm (to search in ordered lists) and Shor’s quantum algorithm (to factorize integer numbers). These applications aim to divulge quantum computing using mobile devices (iPad) and, in addition, they are tools to study new computing methods based on quantum mechanics’ properties. With the same objective, besides the applications, cumulative computing is introduced as a new computing method to solve problems in graph theory.
Una base teorica sobre fisica quantica, computacio quantica i models matematics constitueix el punt de partida per al desenvolupament de la col·leccio d'aplicacions Quantum Graph Tool. Es tracta de sis aplicacions per al sistema operatiu iOS relacionades amb el mon de la computacio quantica i la teoria de grafs. Mes concretament, l'aplicacio central representa un simulador interactiu de circuits quantics que es pot utilitzar per estudiar els algorismes quantics mes coneguts. Aquestes aplicacions pretenen divulgar la computacio quantica mitjancant els dispositius mobils.
Una base tèorica sobre física quàntica, computació quàntica i models matemàtics constitueix el punt de partida per al desenvolupament de la col·lecció d'aplicacions Quantum Graph Tool. Es tracta de sis aplicacions per al sistema operatiu iOS relacionades amb el món de la computació quàntica i la teoria de grafs. Més concretament, l'aplicació central representa un simulador interactiu de circuits quàntics que es pot utilitzar per estudiar els algorismes quàntics més coneguts. Aquestes aplicacions pretenen divulgar la computació quàntica mitjançant els dispositius mòbils.
For decades, classical computers have been governed by predictable rules. But as we approach the physical limits of computation, a new paradigm is emerging. Quantum computing operates on the strange and powerful laws of quantum mechanics—superposition, entanglement, and interference—to tackle problems far beyond the reach of any classical machine. The true potential of this field was unlocked by two landmark discoveries: Shor’s algorithm, a revolutionary method for integer factorization that threatens to upend modern cryptography, and Grover’s algorithm, a versatile tool that offers a quadratic speedup for unstructured search problems. This paper serves as a guide to these foundational algorithms, detailing their inner workings and their profound impact. We also explore post-quantum cryptography, hybrid frameworks, and quantum machine learning—illustrating the evolving role of quantum algorithms in shaping the future of science and technology.
Quantum algorithms are well-known for their quadratic if not exponential speedup over their classical counterparts. The two widely-known quantum algorithms are Shor’s quantum factoring algorithm and Grover’s quantum search algorithm. Shor’s quantum factoring algorithm could perform integer factorization in O(logN). Grover’s quantum search algorithm could solve the unsorted search problem in O(√N). However, both algorithms are introduced as theoretical concepts in the original papers due to the limitations of quantum technology at that time. In this paper, an improved way is presented to realize the two algorithms into a web application using state-of-the-art quantum technology. The web-app is designed and built considering the uses of a quantum simulator and libraries provided by ProjectQ and Rigetti Forest. The result shows that both algorithms are realizable into web-applications.
This paper's aim is to explore improvements to, and applications of, a fundamental quantum algorithm invented by Grover\cite{grover}. Grover's algorithm is a basic tool that can be applied to a large number of problems in computer science, creating quantum algorithms that are polynomially faster than fastest known and fastest possible classical algorithms that solve the same problems. Our goal in this paper is to make these techniques readily accessible to those without a strong background in quantum physics: we achieve this by providing a set of tools, each of which makes use of Grover's algorithm or similar techniques, which can be used as subroutines in many quantum algorithms.}{The tools we provide are carefully constructed: they are easy to use, and in many cases they are asymptotically faster than the best tools previously available. The tools we build on include algorithms by Boyer, Brassard, Hoyer and Tapp, Buhrman, Cleve, de Witt and Zalka and Durr and Hoyer.}{After creating our tools, we create several new quantum algorithms, each of which is faster than the fastest known deterministic classical algorithm that accomplishes the same aim, and some of which are faster than the fastest possible deterministic classical algorithm. These algorithms solve problems from the fields of graph theory and computational geometry, and some employ dynamic programming techniques. We discuss a breadth-first search that is faster than Θ(edges) (the classical limit) in a dense graph, maximum-points-on-a-line in O(N3/2lgN) (faster than the fastest classical algorithm known), as well as several other algorithms that are similarly illustrative of solutions in some class of problem. Through these new algorithms we illustrate the use of our tools, working to encourage their use and the study of quantum algorithms in general.
Early researchers attempting to simulate complex quantum mechanical interactions on digital computers discovered that they very quickly consumed the computers’ available memory\nresources, because the state space of a quantum system typically grows exponentially with problem size. Consequently, Richard Feynman proposed in 1982 that perhaps the only way to simulate complex quantum mechanical situations was by simulating them on some quantum mechanical system. Quantum computers attempt to exploit this idea incorporating the special properties of quantum mechanics, such as the superposition of states and entanglement, into a computing device. Two key algorithms have been discovered which would run on this new type of computer, Shor’s factorization algorithm discovered in 1994, which provides an exponential speedup over classical algorithms and Grover’s search algorithm in 1996, which provides a quadratic speedup. Following this in 1999 Meyer initiated the field of quantum game theory by introducing quantum mechanical states into the framework of classical game theory. In this thesis, we firstly investigate the phase estimation procedure, due to its importance as the basis for Shor’s factorization algorithm, for which a new error formula is found using an improved symmetrical definition of the error. Unlike other existing error formulas which require approximations in their derivation, our result is obtained analytically. The work on the phase estimation procedure then motivates the development of computer software written in the Java programming language, which can simulate the common algorithms and visually display their behavior on a circuit board type layout. The software is found useful in verifying the new error formula described above and to test ideas for new algorithms. Being written in Java, it is envisaged that it could be placed online and used as a learning tool for new students to the field. We then investigate the second key algorithm of quantum computing, the Grover search algorithm. It is already known that the Grover search is an SU(2) rotation but the idea is extended by deriving the three generators in terms of the two non-orthogonal basis vectors, representing the solution and initial states. We then demonstrate that the Grover search is equivalent to the precession of the polarization axis of a spin- 1/2 particle in a magnetic field. At this point we introduce geometric algebra (GA), because of its efficient implementation of rotations and its associated visual representation, and hence ideal to describe the Grover search process. It was found to provide a simple algebraic solution to the exact Grover search problem as well providing a simple visual picture describing the general solution to Meyer’s quantum penny flip game, which is a simple two-player quantum game based on the manipulation of a single qubit and hence closely analogous to the Grover search process. We then extend the work on quantum games developing two-player, three-player and N player quantum games in the context of an EPR type experiment, which has the advantage of providing a sound physical basis to quantum games avoiding the common criticism of other quantum game frameworks regarding the proper embedding of the classical game. Using the algebraic approach of GA, we solve the general N player game, without requiring the use of matrices which become unworkable for large N. Games based on non-factorisable joint probabilities were then also developed which provided a more general framework for both classical and quantum games, and allows the field of quantum games to be accessible to nonphysicists, as it does not employ Dirac’s bra-ket notation. In summary, several new results in the field of Quantum computing were produced, including an improved error formula for phase estimation [JMCL11b], a general solution to Meyer’s quantum penny flip game [CILVS09] and a paper producing quantum games from non-factorisable joint probabilities [CIA10], as well as an EPR framework for quantum games [JMCL11a], refer attached papers.