THE QUANTUM COMPUTER

 

A classical computer performs operations using classical bits, which can be either 0 or 1.
In contrast, quantum computer uses quantum bits or qubits.
Qubits can be 0 and 1 at the same time.
N bits = 2^N qubits

There are many physical objects that can be used as a qubit. Like, a photon, a nucleus or an electron.

How does this work?
All electrons have magnetic fields, so they are basically like tiny bar magnets. (The Spin Property)
In classical bits these electrons can be either in up spin (1) and down spin (0), but in qubits they can be in both state at once.
If you measure the spin of the electron, you'll find it either in upstate or down state but before measuring it the electrons are in a quantum superposition i.e., it is in both the states simultaneously.
A famous example of quantum superposition can be Schrodinger cat experiment.

Quantum Entanglement also is a property of qubit. In which if you know the spin of one of the qubits you can directly deduce the spin of other, no matter how far they are.

A classical computer has logic gates whereas a quantum computer has quantum gates
A quantum gate manipulates an input of superpositions, rotate probabilities and produce another superposition as its output.

By using the properties of superposition and entanglements quantum computers can exponentially be more efficient than a classical computer. Uses
1. IT security
2. Database searching
3. AI
4. Financial modelling
5. Product development Myth = Quantum Computer are universally faster.
Fact = Quantum Computer are only faster for special type of calculations where you have to use different types of quantum superposition available to you at the same time to do some time of quantum computation.