Mariia Mykhailova - Q# Pocket Guide: Instant Help for Q# Developers

by Mariia Mykhailova

Copyright 2022 Mariia Mykhailova. All rights reserved.

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978-1-098-10886-1

[LSI]

When I first learned in the late 90s of a different model of computation, I was instantly inspired and intrigued. How could there be another way for a computer to compute? How would that machine perform operations? What would it mean to program such a machine? My fascination led to my two-decade exploration of answers to such questions, an exploration that now is witness to a growing community of quantum developers, engineers, researchers, and enthusiasts, and an industry working to realize quantum advantage, the demonstration of an algorithm running on a quantum computer that gives a solution more powerful or faster than the best-known classical solution.

But the real impact comes when quantum advantage is practicalwhen we have solutions for practical problems of real-world interest, and those solutions have practical runtimes of less than a few weeks.

Practical is essential. As a computer scientist, I see the magic of quantum computers through the lens of a language, and through the ability to program, form a recipe, and efficiently express what we need the machine to do. The underlying instructions, operations, and programming model of a quantum computer are just different, and we need a different way to program ita practical way that artfully captures the interplay between the highly hybrid nature of quantum algorithms and their quantum and classical needs.

And practicality is what comes to mind in reading Mariias new book. Over the last five years, Mariia, along with a broader team of quantum software engineers and researchers, has been building out a new way to express programs for a quantum computer, and working to make it easier to bring quantum mechanical properties to life through simple, expressive language and examples.

We know that improvements in hardware performance can drive changes in whats possible, and so too can changes in algorithms. An entire industry is working to scale up quantum machines, with a focus on improving the quantum chip and devices. But to achieve quantum advantage, and to chip away at even more advances and areas in which quantum computers will make a difference, we need more algorithms, and we need more practical algorithms.

With the introduction of Fortran, algorithm designers became more efficientby using a more practical language for their needs, they were able to express algorithms and programs faster. They were able to bring their intuition to their code. They were readily able to explore the vast set of opportunities for a classical machine.

We need a similar capability in quantum computing. The Q# programming language has been designed to enable algorithm development, not just low-level instruction programs, and aims to empower the programmer to think about the algorithm design rather than the details of the physics.

With this pocket guide, Mariia brings to life her own experience in quantum development with Q#, weaving her expert perspectives and insights into simple, easy-to-use definitions, examples, and debugging tools. Mariia showcases the nuances of quantum programming, the unique features of Q# that enable more extensive algorithm development, and how to use advanced features of the language to bring your program to quantum life.

I hope this guide enables you to join the exploration for more quantum applications and helps seed a generation of quantum developers and algorithm designers. Developing practical quantum advantage requires our collective intelligence and a growing community of quantum programmers. Quantum programming must be practical for the scale of development needed to happen. And this guide is your next step toward quantum practicality. You never knowyou may just invent the next groundbreaking quantum application.

Dr. Krysta M. Svore

Distinguished Engineer, VP

Quantum Software, Microsoft

May 2022