Intro to Qubits

Qubits are the most fundamental unit of any quantum computer, in much the same way bits are the most fundamental unit of any classical computer.

1. Classical Binary

Before we get too deep into talking about quantum bits, lets first try to understand their classical counterpart. One bit can represent one of two states, just like a light switch can be either ON or OFF at any given point in time. These two states in binary are represented as follows:

• 1 is ON

• 0 is OFF

Because large amounts of data can’t be represented as just 1 or 0, bits are chained together. For example, with two bits you can store these 4 values:

• 00

• 10

• 01

• 11

Each bit you add exponentially increases the total number of possible values that can be stored. Mathematically speaking, the number of values that can be expressed with \(n\) bits is equal to exactly \(2^{n}\).