Quantum computers make use of the principles of quantum mechanics like entanglement, superposition and quantum states to work with data at speeds far greater than that of the classical computers in use today.

## How do quantum computers work?

As mentioned earlier, quantum computers work by using the principles of the one of the pillars of modern physics: **quantum physics**.

To understand how quantum computers work, the working of classical computers should be understood first. The processing unit of a computer is the **microprocessor, **which has tiny microscopic transistors. A microprocessor processes data in the form of strings of 0s and 1s called **binary data** measured in **bits.** A bit is either 0 or 1. Data in the form of 0s and 1s is based on the state of electrical signals. An ‘on’ signal represents 1 and an ‘off’ signal represents 0.

A transistor turns signals on and off and thus contributes to the processing of data. Modern powerful computers have processors which contain billions of tiny transistors so that computers can easily operate on large scale data. The size of each transistor in microprocessors has been decreasing steadily with the progress of technology. Eventually, the each transistors will reach the size of an atom as there is a limit to how many of them can be fitted in a microprocessor, that is when quantum computers come into play.

Things work differently in the quantum world than in our macroscopic classical world. Quantum data consists of **qubits. **A qubit is also 0 or 1, but there is a catch to it; it can be both at the same time. As we approach the size of an atom, data cannot be based on electrical signals since electrical signals themselves are flow of electrons. Instead of associating 0s with off signals and 1s with on signals, they are associated with spin-down and spin-up states of quantum particles respectively.

Let’s take an electron for example, an electron can be in both a spin-up state and a spin-down state at the same time, a phenomena which is called **superposition**. So, we can say that an electron carries a ‘0’ and a ‘1’ at the same time in a quantum processor. An electron locks into one of the two states when light is shone upon it to measure its state, this can be taken advantage of in a quantum computer.

There are **2 ^{4 }**possible configurations of four classical bits, of only one can be used. However, four qubits can exist in all those configurations at the same time thus providing more processing power. So, algorithms could be written to take advantage of quantum superposition and perform large calculations fast.

That is how quantum computers work.

## Why go quantum in computers?

There is a limit to the number of components that can be fitted in a microprocessor and so there is a limit to the calculating and processing power of classical computers.

Quantum computers can help in processing, calculating, analyzing and predicting large streams of data at speeds far greater than modern classical computers.

Following are some of the areas where quantum computers can be of help:

### • Artificial Intelligence | Machine Learning

Machine learning involves numerous complex algorithms and data sets which have to be processed rigorously. Quantum computers can analyze and integrate huge data sets involved in AI fast, which will prove to be a great improvement over classical computers.

Quantum computing can prove to be a catalyst in the process of the rise of Artificial Intelligence which if implied correctly can be extremely useful to mankind.

### • Cybersecurity

Cybersecurity is one of the main concerns in the modern world. As connectivity increases, more and more data is susceptible to theft and damage. Although, complex security frameworks are programmed and used on the internet, there are still many cyber-attacks. Quantum computers can solve many problems of cybersecurity by vastly improving on encryption.

Random number generation for keys can be done much quicker and more efficiently with quantum computers. Applications of quantum computers on machine learning can help in improving cybersecurity too. Anther application of quantum computing could be blockchain technology.

### • Drug Development

Although the most challenging task for quantum computers, drug development can be made much cheaper (in the long run) and time-efficient. Classical computers used today for developing drugs and medicines are slow in analyzing and predicting the behavior of the molecules, quantum computers could perform these tasks much quicker and thus could help in the production of drugs necessary for the treatment or cure of fatal diseases.

### • Weather Forecasting

It is very hard to predict weather patterns with accuracy using modern supercomputers. A lot of data needs to be processed which includes many variables with intricate details, quantum computers in link with machine learning can help in solving many problems involved in making climate models.

In the era of climate change awareness, accurate weather forecasting will be of utmost importance, and quantum computers could certainly play a key role in understanding climate change.

### • Financial Modelling

Profits and losses, risks and fruit in investments etc., are dependent on many variables which are processed by classical computers to make financial models. These models help investors to survive in the market.

This process involves many complex calculations which take a lot of time to be done by conventional computers. Quantum computers can help in financial modelling by improving the quality of the result.

## Limitations

Although quantum computers are the next big thing and could potentially bring another revolution in the world of computer science, there are some problems in getting there.

Quantum computers are extremely hard to design and engineer. Complex algorithms need to be written to access the processing power of qubits.

Moreover, quantum computers face the problem of ‘quantum decoherence’. Decoherence is the loss of coherence and coherence means the ability of a quantum state to maintain its superposition and entanglement.

So as long as quantum states are coherent, quantum computers can function. And the only data-related way that quantum computers can function is if the data remains long enough to be processed, but scientists have found out that coherence spontaneously disappears over time and with that data as well.

Quantum computers will be of no better use in daily use like gaming, streaming videos or typing a document. All these tasks require classical algorithms, they do not require parallel processing of a quantum computer. Quantum computers will only be of use in complex calculations on a higher level.

## Conclusion

Quantum computers will definitely prove to be one of the greatest achievements in the technological world once its technology gets out of infancy. Google with its ‘quantum supremacy‘ experiment has already proved that quantum computers can process information and give its output way faster than a classical computer.

In the coming years, governments and large companies will definitely make work of quantum computers to solve the most complex of problems of the world and after that quantum computers may even become commonplace.

The world of technology is pacing increasing fast day by day, it is only a matter of time before mankind becomes invincible with its marvelous inventions such as quantum computers.