What is Quantum Computing & Quantum Key Distribution?
Quantum computing is the use of superposition, interference, and entanglement phenomena of quantum mechanics to perform computation. Superposition is the ability of the quantum system to be in multiple states at the same time as if I make a classical analogy, then what you will hear when you play two musical notes at once is known as a superposition of two notes.
Entanglement describes an extremely strong correlation that exists between quantum particles even though they are a great distance apart. Quantum interference is very much similar to wave interference in which quantum states can undergo interference.
Quantum computers can stimulate the development of new technology in science, machine learning methods to diagnose illness sooner, medications to save many lives, materials to make more efficient structures and devices, and some forecasting and predictions to be prepared for the future.
For problems above a certain size and complexity, we don’t have that much computational power to tackle them that is where their roles come into the picture. When every machine, everything just gives up thinking and examining, Quantum computing is the only and last hope.
All computer systems are based on a fundamental ability to manipulate information and store it more efficiently. The major difference between current computers are quantum computers is the current computers stored information in bits format as binary 0 or binary 1 states.
Whereas quantum computers use quantum-mechanical phenomena to manipulate information for this they rely on quantum bits or qubits.
There are different ways to create a qubit. superconductivity is the one method to create and maintain a quantum state. As superconductivity works at absolute zero temperature so any heat in the system can introduce error, that is why quantum computers operate at a temperature close to absolute zero.
The theory of quantum computing begins with German physicist Werner Heisenberg. He introduces the uncertainty principle, which means the position and momentum of quantum particles cannot be determined at the same time.
Stephen Wiesner and Charlie Bennett make the first use of the phrase “quantum information theory” and they give the first suggestion for using entanglement as a communication resource.
Quantum key distribution relies on another interesting property of quantum mechanics that defines any attempt to observe or measure a quantum system will going the disturb the quantum system.
The home to one of the few QKD prototypes in the world is the Institute for Quantum Computing (IQC). “Alice” is a device located at IQC headquarters that receives half of the entangled photon pair generated by a laser on the roof of a building at the University of Waterloo. And “Bob” is housed at the nearby Perimeter Institute and receives the other half of the entangled photons of the same laser.
Photons have a unique measurable property called polarization. An individual photon can be described as having the right or left circular polarization or having horizontal 0r vertical polarization, or a superposition of the two.
Since the polarization of each photon is always random, you can never know the unique properties of each photon in advance. But here is a point that makes entanglement interesting, if Alice and Bob measure the polarization of the entangled photons they receive the same.
Depending on the polarization of each photon, Alice and Bob describe either a “one” or a “zero” to each photon they receive. Therefore, if Alice gets a string like 011010, Bob also gets a 011010. Unless there is not any disturbance in the system, Alice and Bob will instantly notice that their keys don’t match.
Quantum computers provide no additional advantages over classical computers in terms of computability, but for certain problems, quantum algorithms have significantly lower time complexities than corresponding known classical algorithms.
