Book Image

Quantum Computing in Practice with Qiskit® and IBM Quantum Experience®

By : Hassi Norlen
5 (1)
Book Image

Quantum Computing in Practice with Qiskit® and IBM Quantum Experience®

5 (1)
By: Hassi Norlen

Overview of this book

IBM Quantum Experience® is a leading platform for programming quantum computers and implementing quantum solutions directly on the cloud. This book will help you get up to speed with programming quantum computers and provide solutions to the most common problems and challenges. You’ll start with a high-level overview of IBM Quantum Experience® and Qiskit®, where you will perform the installation while writing some basic quantum programs. This introduction puts less emphasis on the theoretical framework and more emphasis on recent developments such as Shor’s algorithm and Grover’s algorithm. Next, you’ll delve into Qiskit®, a quantum information science toolkit, and its constituent packages such as Terra, Aer, Ignis, and Aqua. You’ll cover these packages in detail, exploring their benefits and use cases. Later, you’ll discover various quantum gates that Qiskit® offers and even deconstruct a quantum program with their help, before going on to compare Noisy Intermediate-Scale Quantum (NISQ) and Universal Fault-Tolerant quantum computing using simulators and actual hardware. Finally, you’ll explore quantum algorithms and understand how they differ from classical algorithms, along with learning how to use pre-packaged algorithms in Qiskit® Aqua. By the end of this quantum computing book, you’ll be able to build and execute your own quantum programs using IBM Quantum Experience® and Qiskit® with Python.
Table of Contents (12 chapters)

Chapter 9: Grover's Search Algorithm

In this chapter, we will take a look at a fairly well-known quantum algorithm: Grover's search algorithm. We will learn how to code it by building our own circuits for the following variations: a 2-qubit version, a 3-qubit version, and a 4- and more qubit version, to see how the complexity of the circuit grows with the number of qubits.

We will run our algorithm both on a local simulator and on an IBM Quantum® backend and will see how the algorithm works pretty well on the relatively short circuit that is required for a 2-qubit Grover, but not as well on the much larger circuits that are required for more qubits. The number of gates in your circuit gets successively larger, and the various errors that we explored in Chapter 8, Cleaning Up Your Quantum Act with Ignis, start to dominate.

In this chapter, we will cover the following recipes:

  • Exploring quantum phase kickback
  • A quick interlude on classical search
  • ...