# Quantum Computers: What They Are and How They Work

## Discover what quantum computers are, how they work, and why they’re key to solving complex problems faster than traditional computers.

The UK has launched its first quantum computing hub called National Quantum Computing Centre (NQCC). But what exactly is quantum computing, how is it different from regular computing and what could it do for us in the future?

Right now, there are only six quantum computers in the UK but quantum computing is growing fast. Experts estimate this market could reach £55 billion by 2035. For industries like finance, chemistry, life sciences and transportation, quantum computing could create around £1.5 trillion in economic benefits.

At the NQCC, located in Harwell, Oxfordshire, and run by the Science and Technology Facilities Council (STFC), there are plans to build 12 more quantum computers. Private companies will build eight, and government scientists will build four.

The next big technological revolution could be quantum computing, which would help us address some of the most pressing issues facing the globe.

**What Makes Quantum Computing Essential?**

To grasp how different quantum computers are, it helps to first understand how regular computers work.

Your home computer, phone, or smartwatch processes information using “bits,” which are either a one or a zero. These bits come from transistors that can be switched on (one) or off (zero).

In the early days of computing, each bit was made from a vacuum tube. For example: Colossus machine, built in 1943 for code-breaking, had 1,600 bits and weighed a ton, filling entire room.

Today, vacuum tubes are unnecessary because of the silicon revolution. With 512 billion bits, even a standard mobile phone processor—smaller than your thumbnail—can perform endless calculations.

Ordinary computers have drawback of carrying out computations one at a time. Every bit must be altered sequentially & can only ever be a one or a zero. This implies that one computation must be completed before beginning the next.

This problem is solved by quantum computers, which use ideas from quantum physics to execute several calculations simultaneously. However, how do they accomplish this?

**Bits and Qubits Explained**

In quantum computers, the basic unit of computation is called a qubit, which replaces the regular bit. Unlike bits which use transistors, qubits are made from tiny particles like atoms, electrons or photons.

There are different ways to create qubits. For instance: one machine at the NQCC uses rubidium atoms held in place by laser beams. All qubits benefit from a unique feature of quantum mechanics known as **quantum superposition**.

Superposition allows a particle or photon to exist in multiple states at once. For example, it can spin both up and down at the same time and only settles into one state when observed. You can think of it like a spinning coin—it exists as both heads and tails while it’s in the air, but once it lands, it “decides” on one side.

## Quantum ‘Loophole’ Concept

The unique ability of qubits to exist in multiple states at once, similar to **Schrödinger’s cat**, allows quantum computers to overcome the limitations of regular computers, which process calculations one at a time. Since a qubit can represent both one and zero simultaneously, it can produce many possible outcomes at once.

However, having just one bit or qubit isn’t very useful. Like regular computers, the more qubits you have, the faster and more complex calculations you can perform.

For traditional computers, adding more bits is simply done by creating more on a silicon chip. But with quantum computers made of individual floating atoms, the challenge is figuring out how to create more qubits and, more importantly, how to get them to communicate with each other.

**What is Quantum Entanglement?**

To make qubits work together, scientists use a fascinating phenomenon called **quantum entanglement**. This allows them to create networks of **entangled** qubits where all their superposition states are linked.

In simple terms, quantum entanglement means that two or more particles are connected like a quantum wifi network. This connection enables qubits to instantly respond to changes in each other’s states, no matter how far apart they are. So, if you measure one entangled qubit, you can immediately know the properties of its partner without needing to check it directly.

More entangled qubits you have in a quantum computer, the more calculations it can perform—and the faster it can do them. Since each qubit can exist in multiple states at once, adding more entangled qubits increases the number of calculations exponentially.

What does this mean in real terms? For instance, a quantum computer with 1,180 qubits (fewer than the 1,600 bits in the Colossus) would have more entangled states than there are individual atoms in the entire Universe.

This allows a quantum computer to theoretically run every possible calculation at the same time, instead of having to repeat a calculation multiple times like a traditional silicon processor.

## How Can Quantum Computing Be Used?

Imagine you run a delivery company (let’s call it after a famous rainforest), and you need to find the best route from point A to point B while making 150 stops along the way.

A regular computer would analyze each possible route one by one, comparing them to find the most efficient option. With potentially tens of thousands of routes, this process could take a long time.

In contrast, a quantum computer can evaluate many routes at once, allowing it to quickly determine the best one. This means it can perform complex calculations with many variables much faster.

The key takeaway is that quantum computers can handle nearly unlimited calculations simultaneously, giving them amazing abilities for real-time optimization and pattern recognition.

As a result, quantum computers are expected to be incredibly useful for banks, helping detect fraud. They can provide insights into complex natural systems that traditional computers struggle with, such as predicting weather patterns, understanding climate change, and studying how drugs interact with cancer—potentially saving lives and protecting our planet.

However, there’s a downside: quantum computers could easily break current data encryption systems, creating challenges for spy agencies and sparking a race between developing quantum-based encryption and countering quantum hacking.

**Need Some Quiet Time**

Unfortunately, scaling up a quantum computer isn’t as simple as just adding more qubits and connecting them. While you can easily add bits to a regular computer, adding more qubits to a quantum computer makes the system more unstable and harder to manage. This makes it very challenging to increase the power of a quantum computer.

Superposition and entanglement, which are key features of qubits, are also very fragile. Even minor disturbances, like vibrations or radiation, can disrupt these states. This issue, known as **quantum decoherence**, means that if a qubit gets “broken,” it has to be replaced.

To prevent this, qubit-based processors need to be carefully isolated from their surroundings. This involves using vacuums, dampening vibrations, and shielding against radiation.

This challenge of scaling up is what centers like National Quantum Computing Centre are trying to solve. However, it also suggests that you probably won’t see a quantum computer on your desk or in your pocket anytime soon. Instead, the future of computing will likely combine qubits with traditional binary bits.

- Simple Ways to Untag Yourself From Facebook Posts
- How to Enable Auto-Lock on Your Android Device for Maximum Security
- A Taste of 6G: Wireless Data Transmission Over 9,000 Times Faster Than 5G

## Quantum Computers Conclusion

The UK’s new National Quantum Computing Centre is a major quantum technology breakthrough that might transform industries like banking, healthcare and transportation. Quantum computers may answer complex problems much faster than traditional computers because of the significant differences in their operation.

However, it is difficult to create and scale quantum computers. They are difficult to stabilize & grow because they are extremely sensitive to external factors. Notwithstanding these obstacles, organizations such as NQCC are striving to resolve them bringing us one step closer to time when quantum computers may collaborate with conventional computers to address some of our most pressing problems.