Book Image

Dancing with Qubits

By : Robert S. Sutor
5 (1)
Book Image

Dancing with Qubits

5 (1)
By: Robert S. Sutor

Overview of this book

Quantum computing is making us change the way we think about computers. Quantum bits, a.k.a. qubits, can make it possible to solve problems that would otherwise be intractable with current computing technology. Dancing with Qubits is a quantum computing textbook that starts with an overview of why quantum computing is so different from classical computing and describes several industry use cases where it can have a major impact. From there it moves on to a fuller description of classical computing and the mathematical underpinnings necessary to understand such concepts as superposition, entanglement, and interference. Next up is circuits and algorithms, both basic and more sophisticated. It then nicely moves on to provide a survey of the physics and engineering ideas behind how quantum computing hardware is built. Finally, the book looks to the future and gives you guidance on understanding how further developments will affect you. Really understanding quantum computing requires a lot of math, and this book doesn't shy away from the necessary math concepts you'll need. Each topic is introduced and explained thoroughly, in clear English with helpful examples.
Table of Contents (16 chapters)
Preface
13
Afterword

3.3 Integers

People are sometimes confused by negative numbers when they first encounter them. How can I have a negative amount of anything? I can’t physically have fewer than no apples, can I?

To get around this, we introduce the idea that a positive number of things or amount of money means something that you yourself have. A negative number or amount means what you owe someone else.

If you have $100 or €100 or ¥100 and you write a check or pay a bill electronically for 120, one of two things will likely happen. The first option is for the payment to fail and your bank may charge you a fee. The second is that the bank will pay the full amount, let you know that you are overdrawn, and charge you a fee. You will then need to pay the amount overdrawn quickly or have it paid from some other account.

Whatever currency you used, you started with 100 and ended up with −20 before repayment. You owed the bank 20. If you deposit 200 in your account...