Summary
To my beloved parents and also to my beloved wife, daughter, and son, who made it possible for me to write this book.
Preface
With the advent of nanotechnology, quantum computing is increasingly playing a large role in developing more compact and lower power consumption computers. The use of the properties of quantum mechanics has increased the speed certain computations dramatically. Quantum computing is one of the most promising nanotechnologies for designing modern compact computers. The quantum computer is an entirely different concept than the traditional computer and it does not use binary logic. Quantum computers can assess more than one probability at a time through something called quantum entanglement.
The switching and memory units of a computing system are becoming as small as an atom, and switching techniques have reached their peak of development. Therefore, it is necessary to discover an entirely new way of thinking to build computing machines. Recently, advances in mathematics, materials science, and computer engineering have transformed quantum computing machines from theory to practice.
This quantum computing book covers basic quantum computing, fault-tolerant quantum computing, and quantum dot cellular automata (QCA). The basic quantum computing part of this book comprises designs for different quantum circuits, including the adder, multiplier, divider, encoder, decoder, barrel shifter, comparator, and arithmetic logic unit. These quantum circuits are the building blocks of a quantum computer. Readers will obtain an understanding of quantum computing from the basic to the advanced level, which will help them to design new quantum circuits.
The discovery of quantum error correction has greatly improved the long-term prospects for quantum computing technology. Encoded quantum information can thus be protected from the errors that arise due to uncontrolled interactions with the environment, or due to imperfect implementations of quantum logical operations. The fault-tolerant quantum computing part of this book consists of the designs for different fault-tolerant quantum circuits, such as the adder, multiplier, and divider. Fault tolerance is a very complex part of making a quantum circuit. It is necessary to develop fault-tolerant circuits which allow the qubits to be protected from quantum errors produced by inadequate control of environmental interactions. Readers will obtain a clear understanding of fault-tolerant quantum circuits and will be able to design their own fault-tolerant circuits.
QCA are a new computational paradigm which encode binary information by charge configuration within a cell instead of the conventional current switches. As there is no current flow, the Coulombic interaction is sufficient for computation. This revolutionary paradigm provides a possible solution for transistorless computation at the nanoscale. Readers will obtain knowledge on QCA and the design processes of different quantum circuits using QCA design software. They will be acquainted with the costs of QCA circuits, which include cell area, delay, kink energy, and power.
As a whole, this book is a great resource for quantum computing researchers and students alike. There are very few books written in this field. This book will satisfy the interest of beginner to advanced level readers.
Acknowledgments
I would like to express my sincerest gratitude and particular appreciation to the various researchers in the field of quantum computing. The contents in this quantum computing book have been compiled from a wide variety of research works, where the researchers are pioneers in their respective fields. All the research articles related to the contents are listed at the end of each chapter.
I am grateful to my parents and family members for their endless support. Most of all, I want to thank my wife Mrs Sitara Roshan, my daughter Ms Fariha Tasnim, and my son Md Tahsin Hasan for their invaluable cooperation in completing this book.
Finally, I am also grateful to all of those who have provided their support and valuable time to finish this book.
Author biography
Hafiz Md Hasan Babu
Dr Hafiz Md Hasan Babu is currently working as the Pro-Vice-Chancellor of the National University, Bangladesh. He is on deputation from the Department of Computer Science and Engineering, University of Dhaka, Bangladesh. He is also a Professor and the former Chairman of the same department. Due to his excellent academic and administrative capabilities, he also served as the Professor and founder Chairman of the Department of Robotics and Mechatronics Engineering, University of Dhaka, Bangladesh. He served as a World Bank Senior Consultant and General Manager of the Information Technology & Management Information System Departments of Janata Bank Limited, Bangladesh. Dr Hasan Babu was the World Bank Resident Information Technology Expert of the Supreme Court Project Implementation Committee, Supreme Court of Bangladesh. He was also the Information Technology Consultant of the Health Economics Unit and Ministry of Health and Family Welfare in the project ‘SSK (Shasthyo Shurokhsha Karmasuchi) and Social Health Protection Scheme’ under the direct supervision and funding of the German Financial Cooperation through KfW.
Professor Dr Hafiz Md Hasan Babu received his MSc degree in Computer Science and Engineering from the Brno University of Technology, Czech Republic, in 1992 under a Czech Government Scholarship. He also obtained a Japanese Government Scholarship to pursue his PhD from the Kyushu Institute of Technology, Japan, in 2000. He also received a Deutscher Akademischer Austauschdienst (DAAD) Fellowship from the Federal Republic of Germany.
Professor Dr Hasan is a very eminent researcher. He has received the best paper award at three reputed international conferences. In recognition of his valuable contributions in the field of computer science and engineering, he received the Bangladesh Academy of Sciences Dr M O Ghani Memorial Gold Medal Award for the year 2015, which is one of the most prestigious research awards in Bangladesh. He was also awarded the University Grants Commission (UGC) of Bangladesh Gold Medal Award 2017 for his outstanding research contributions to computer science and engineering. He has written more than one hundred research articles published in reputable international journals (IET Computers & Digital Techniques, IET Circuits and Systems, IEEE Transactions on Instrumentation and Measurement, IEEE Transactions on VLSI Systems, IEEE Transactions on Computers, Journal of Microelectronics (Elsevier), Journal of Systems Architecture (Elsevier), Journal of Quantum Information Processing (Springer), etc) and at international conferences. According to Google Scholar, Professor Hafiz has received around 960 citations with an h-index of 14 and an i10-index of 21. He is a regular reviewer for reputable international journals and international conferences. He has presented invited talks and chaired scientific sessions or worked as a member of the organizing committee or international advisory board at many international conferences held in different countries. For his excellent research record, he has also been appointed as the Associate Editor of Computers and Digital Techniques, published by the Institution of Engineering and Technology of the United Kingdom.
Professor Dr Hasan was appointed as a member of the Prime Ministerʼs ICT Task Force Committee, Government of the Peopleʼs Republic of Bangladesh, on recognition of his national- and international-level contributions to engineering sciences. He is currently the President of the Bangladesh Computer Society and also the President of the Internet Society, Bangladesh Chapter. He has been recently appointed as a part-time member of Bangladesh Accreditation Council to ensure the quality of higher education in Bangladesh.
Part I
Quantum logic
An overview of quantum circuits
