Superposition frees us of from binary constraints. A quantum computer

**works**with particles that can be in superposition. Rather than representing bits — such particles would represent**qubits**, which can take on the value 0, or 1, or both simultaneously.Correspondingly, how is quantum computer made?

A classical

**computer**has a memory**made**up of bits, where each bit is represented by either a one or a zero. A**quantum computer**maintains a sequence of qubits. An example of an implementation of qubits of a**quantum computer**could start with the use of particles with two spin states: "down" and "up" (typically written.What is a qubit system?

A

**qubit**is a two-state quantum-mechanical**system**, such as the polarization of a single photon: here the two states are vertical polarization and horizontal polarization. In a classical**system**, a bit would have to be in one state or the other.How many different states are there in a qubit?

A quantum computer maintains a sequence of qubits. A single qubit can represent a one, a zero, or any quantum superposition of those

**two**qubit states; a pair of qubits can be in any quantum superposition of**4 states**, and three qubits in any superposition of**8 states**.