It’s the holy grail of science…. We will be able to do things we couldn’t dream of before

# Introduction

In order to understand Quantum Computing we’ll first need to understand some basics of Quantum Mechanics.

Quantum mechanics including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.

##### The Particlle-Wave dualism

When Quantum Scientists started with studying the elementary particle of light, the photon they made a discovery which they couldn’t really explain. (laser) light, projected on a slit showed a clear intervention pattern, which indicated that light was a wave-form. At the same time, other experiments proved clearly that light also behaved as a particle. This was a contradiction! Physically and Mathematically this was impossible! It’s a contradiction or paradox. As we’ll see further, Quantum Theory is full of these paradoxes.

##### Schreudinger’s Cat

**Disclaimer:** This is not a real experiment with a real cat. It’s a thought experiment. No animals are hurt, it’s purpose is to explain a principal consequence of Quantum Mechanics: The Quantum **Superposition**.

In Quantum Mechanics, multiple states can be true at the same time. This was difficult to accept for many Scientists. Albert Einstein for example said ‘God doesn’t play dice! Yet, everything predicted by the Quantum Theory was unambiguously proven to be right.

The Austrian physicist Erwin Schrödinger in 1935 illustrated what he saw as the problem quantum theory applied to everyday objects. The scenario presents a cat that may be simultaneously both alive and dead, a state known as a **quantum superposition**, as a result of being linked to a random subatomic event that may or may not occur. The thought experiment is also often featured in theoretical discussions of the interpretations of quantum mechanics. Schrödinger coined the term Verschränkung (entanglement) in the course of developing the thought the experiment.

Quantum Theory predicts that it is not possible to know both the state (position) of a particle and observing a subatomic particle will influence it’s state. As long as the box is closed we can not say if the cat is dead or alive. In fact it’s perfectly good to say it’s both!

In the picture below, the cat is locked in a box. There are also a radioactive source, a detector (Geigenteller) and a small bottle with a lethal gas (cyanide). The Geigenteller is connected to a hammer which will fall on the bottle, it breaks and the poisonous gas is released into the box, killing the cat. Everything is constructed in such a way that the hammer will only fall on the bottle when a single particle in the radioactive source decais.

Quantum Computers use Quantum bits or qBits. Where a normal bit can have only 2 statuses (0 or 1), the qbit can have both at the same time. This opens new possibilities in computing!

Processes can now be infinite at the same time, resulting in a infinite fast computer!

##### How real is Quantum Computing?

I can imagine this question. It’s actually the same as How real is the Quantum Theory? The answer to that last question is: Absolutely real! In fact, engineers and chemical engineering work with it daily! Modern chemical industry wouldn’t be possible without Quantum Theory! It’s been more than enough proven to say that it’s more a fact than a theory!

So how real are Quantum Computers?

The answer: Very real! In fact they are manufactured by a company named D-Wave Systems. You can visit their website at:

https://www.dwavesys.com/quantum-computing

IBM is in Quantum Computing too. They have a Quantum Computer online which you can try. It’s here:

https://www.research.ibm.com/ibm-q/

Go ahead and start using it. If you can do something useful with it please comment on this post. I’m curious about everyone’s experience!

According to IBM, Today, quantum computing is a researcher’s playground but in 5 years it will be a mainstream.

In five years, the effects of quantum computing will reach beyond the research lab. It will be used extensively by new categories of professionals and developers looking to this emerging method of computing to solve problems once considered unsolvable.

Google is also in QC (not surprisingly).

Temperature

Many of the quantum computing technologies around the world operate at around **0.1 Kelvin** — just a fraction above absolute zero (-273 degrees Celsius). To keep the technology that cold, scientists need to use special cryogenic refrigeration techniques. This makes it very expensive too operate. Techniques are however developed to operate at higher temperatures. Each degree Kelvin higher saves thousands of dollars!