Quantum Simulation for High Energy Physics

It is for the first time that Quantum Simulation for High Energy Physics (HEP) is studied in the U.S. decadal particle-physics community planning, and in fact until recently, this was not considered a mainstream topic in the community. This fact speaks of a remarkable rate of growth of this subfield over the past few years, stimulated by the impressive advancements in Quantum Information Sciences (QIS) and associated technologies over the past decade, and the significant investment in this area by the government and private sectors in the U.S. and other countries. High-energy physicists have quickly identified problems of importance to our understanding of nature at the most fundamental level, from tiniest distances to cosmological extents, that are intractable with classical computers but may benefit from quantum advantage. They have initiated, and continue to carry out, a vigorous program in theory, algorithm, and hardware co-design for simulations of relevance to the HEP mission. This community whitepaper is an attempt to bring this exciting and yet challenging area of research to the spotlight, and to elaborate on what the promises, requirements, challenges, and potential solutions are over the next decade and beyond.Comment: This is a whitepaper prepared for the topical groups CompF6 (Quantum computing), TF05 (Lattice Gauge Theory), and TF10 (Quantum Information Science) within the Computational Frontier and Theory Frontier of the U.S. Community Study on the Future of Particle Physics (Snowmass 2021). 103 pages and 1 figur

Virtual Reality Applied to Welder Training

Welding is a challenging, risky, and time-consuming profession. Recently, there has been a documented shortage of trained welders, and as a result, the market is pushing for an increase in the rate at which new professionals are trained. To address this growing demand, training institutions are exploring alternative methods to train future professionals with the goals of improving learner retention of information, shortening training periods, and lowering associated expenses. The emergence of virtual reality technologies has led to initiatives to explore their potential for welding training. Multiple studies have suggested that virtual reality training delivers comparable, or even superior, results when compared to more conventional approaches, with shorter training times and reduced costs in consumables. Additionally, virtual reality allows trainees to try out different approaches to their work. The primary goal of this dissertation is to develop a virtual reality welding simulator. To achieve this objective effectively, the creation of a classification system capable of identifying the simulator’s key characteristics becomes imperative. Therefore, the secondary objective of this thesis is to develop a classification system for the accurate evaluation and comparison of virtual reality welding simulators. Regarding the virtual reality welding simulation, the HTC VIVE Pro 2 virtual reality equipment was employed, to transfer the user’s action from the physical to the virtual world. Within this virtual environment, it was introduced a suite of welding tools and integrated a Smoothed Particle Hydrodynamics simulator to mimic the weld creation. After conducting comprehensive testing that revealed certain limitations in welding quality and in the simulator performance, the project opted to incorporate a Computational Fluid Dynamics (CFD) simulator. The development of the CFD simulator proved to be a formidable challenge, and regrettably, its complete implementation was unattainable. Nevertheless, the project delved into three distinct grid architectures, from these, the dynamic grid was ultimately implemented. It also proficiently integrated two crucial solvers for the Navier-Stokes equations. These functions were implemented in the Graphics Processing Unit (GPU), to improve their efficiency. Upon comparing GPU and Central Processing Unit (CPU) performance, the project highlighted the substantial computational advantages of GPUs and the advantages it brings to fluid simulations.A soldadura é uma profissão exigente, perigosa e que requer um grande investimento de tempo para alcançar resultados satisfatórios. Recentemente, tem sido registada uma falta de profissionais qualificados na área da soldadura. Como resultado, o mer cado está a pressionar para um aumento do ritmo a que os novos trabalhadores são formados. Para responder a esta crescente procura, as instituições de formação estão a explorar métodos alternativos para formar futuros profissionais, com o objetivo de melhorar a retenção de informação, encurtar os períodos de treino e reduzir as despe sas associadas. Com o desenvolvimento de tecnologias nas áreas de realidade virtual e realidade aumentada, têm surgido iniciativas para explorar o potencial destas na formação de soldadura. Vários estudos sugeriram que a formação em realidade virtual proporciona resultados comparáveis, ou mesmo superiores, aos de abordagens mais convencionais, com tempos de formação mais curtos e reduções nos custos de consumíveis. Além disso, a realidade virtual permite aos formandos experimentar diferentes abordagens ao seu trabalho. O objetivo principal desta dissertação é o desenvolvimento de um simulador de soldadura em realidade virtual. Para atingir este objetivo de forma eficaz, torna-se imperativa a criação de um sistema de classificação capaz de identificar as características chave do simulador. Assim, o objetivo secundário desta dissertação é desenvolver um sistema de classificação para a avaliação e comparação precisas de simuladores de soldadura em realidade virtual. Relativamente ao simulador de soldadura em realidade virtual, foi utilizado o kit de realidade virtual HTC VIVE Pro 2, para transferir as ações do utilizador no mundo físico para o mundo virtual. No ambiente virtual, foi introduzido um con junto de ferramentas de soldadura e integrado um simulador de Hidrodinâmica de Partículas Suavizadas para simular a criação da solda. Após a realização de testes exaustivos que revelaram algumas limitações na qualidade da solda e no desempenho do simulador, o projeto optou por incorporar um simulador de Dinâmica de Fluidos Computacional (CFD). O desenvolvimento do simulador CFD revelou-se um desa fio formidável e, infelizmente, não foi possível completar a sua implementação. No entanto, o projeto aprofundou três arquiteturas de grelha distintas, das quais foi implementada a grelha dinâmica. O projeto também implementou duas funções cru ciais para resolver as equações de Navier-Stokes. As funções relativas ao simulador de fluidos foram implementadas na Unidade de Processamento Gráfico (GPU), a fim de melhorar a sua eficiência. Ao comparar o desempenho da GPU com o da Unidade Central de Processamento (CPU), o projeto evidenciou os beneficios computacionais das GPUs e as vantagens que trazem para as simulações de fluidos

Control and calibration strategies for quantum simulation

The modeling and prediction of quantum mechanical phenomena is key to the continued development of chemical, material, and information sciences. However, classical computers are fundamentally limited in their ability to model most quantum effects. An alternative route is through quantum simulation, where a programmable quantum device is used to emulate the phenomena of an otherwise distinct physical system. Unfortunately, there are a number of challenges preventing the widespread application of quantum simulation arising from the imperfect construction and operation of quantum simulators. Mitigating or eliminating deleterious effects is critical for using quantum simulation for scientific discovery. This dissertation develops strategies for implementing quantum simulation and simultaneously mitigating error through the use of device control and calibration. First, an example of the benefits of calibration and control on simulator performance is provided through a case study on simulating the classical Shastry-Sutherland Ising model using quantum annealing. Motivated by the increased precision and accuracy provided by such strategies, a paradigm for parameterized Hamiltonian simulation using quantum optimal control is proposed and validated through numerical simulation. Finally, we apply the methods developed to demonstrate the feasibility of using optimal control for simulation of exotic, dynamical quantum phenomena. Specifically, we demonstrate that quantum optimal control can realize the quantum simulation of string order melting in superconducting quantum devices. These results affirm the utility of quantum optimal control methods for quantum simulation tasks and establish new opportunities for applications of quantum computing to the study of phenomena in quantum physics

Quantum trajectories and open many-body quantum systems

The study of open quantum systems has become increasingly important in the past years, as the ability to control quantum coherence on a single particle level has been developed in a wide variety of physical systems. In quantum optics, the study of open systems goes well beyond understanding the breakdown of quantum coherence. There, the coupling to the environment is sufficiently well understood that it can be manipulated to drive the system into desired quantum states, or to project the system onto known states via feedback in quantum measurements. Many mathematical frameworks have been developed to describe such systems, which for atomic, molecular, and optical (AMO) systems generally provide a very accurate description of the open quantum system on a microscopic level. In recent years, AMO systems including cold atomic and molecular gases and trapped ions have been applied heavily to the study of many-body physics, and it has become important to extend previous understanding of open system dynamics in single- and few-body systems to this many-body context. A key formalism that has already proven very useful in this context is the quantum trajectories technique. This was developed as a numerical tool for studying dynamics in open quantum systems, and falls within a broader framework of continuous measurement theory as a way to understand the dynamics of large classes of open quantum systems. We review the progress that has been made in studying open many-body systems in the AMO context, focussing on the application of ideas from quantum optics, and on the implementation and applications of quantum trajectories methods. Control over dissipative processes promises many further tools to prepare interesting and important states in strongly interacting systems, including the realisation of parameter regimes in quantum simulators that are inaccessible via current techniques.Comment: 66 pages, 29 figures, review article submitted to Advances in Physics - comments and suggestions are welcom