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

2.5 Addition, logically

Using binary arithmetic as we discussed in section 2.2

0 + 0 = 0
1 + 0 = 1
0 + 1 = 1
1 + 1 = 0 carry 1

Focusing on the value after the equal signs and temporarily forgetting the carrying in the last case, this is the same as what xor does with two inputs.

tikz JPG figure

tikz JPG figure

We did lose the carry bit but we limited ourself to having only one output bit. What gate operation would give us that 1 carry bit only if both inputs were also 1, and otherwise return 0? Correct, it’s and! So if we can combine the xor and the and and give ourselves two bits of output, we can do simple addition of two bits.

Question 2.5.1

Try drawing a circuit...