The building blocks of quantum computers
The basic building block of a quantum computer is the qubit. Qubits in QC are similar to bits in classical computing, but they behave very differently. Let's learn more about qubits.
Qubits
Classical bits can hold only a position of 0 or 1, but qubits can hold positions between 0 and 1, and multiple positions at once. Qubits are quantum systems that scientists and engineers can control. Some examples of qubits are atoms, molecules, and photons.
Quantum states are represented by the little flags "
", called Dirac notation. A single classical bit is denoted by 0 or 1, while a single quantum bit (qubit) is denoted by complex linear combinations of 
and 
. Qubits are two-dimensional vectors with complex coefficients, as shown below:
Figure 16.1: Bloch sphere – abstract representation of a qubit
In the preceding diagram, a qubit is represented using a Bloch sphere. A Bloch sphere is a representation of...
