- Vijay Sethi

# Quantum Computers no longer a science fiction

Digital technologies are changing our lives in a big way. Industries are welcoming a set of emerging technologies - Distributed Ledger Technology, Artificial Intelligence, Extended Reality, and Quantum Computing (DARQ) - which will play a huge role in innovation. A few months back, I joined as the chairman of the advisory board of BosonQ Psi, an Indian startup, which is working with Quantum Computing. They are developing ground-breaking quantum computing powered engineering simulations to aid industries such as aerospace, automotive, energy, manufacturing, biotechnology, etc. which could potentially save millions of dollars by reducing time and enhancing accuracy to make significant design changes in their product lifecycle. When I interact with my professional colleagues and acquaintances about Quantum Computing, I realize that the general awareness about Quantum Computing is less. Hence I thought of sharing my thoughts on 3 questions that have come up frequently in my discussions about Quantum Computers – the systems that power the ‘Q’ in DARQ.

**First - Are Quantum computers a reality?**

The answer is yes. Quantum computers today are no longer considered to be science fiction. In the second wave of Quantum technology, it has advanced from theoretical research in physics labs to being successfully adopted by governments and industries in a developing commercial landscape. Huge amount of work is going on in this field – be it in hardware or in software – across the globe including India. Many organizations in aerospace, automotive, and other industries have started using or piloting quantum computing to implement change in their product life cycle. Interestingly, major IT companies and start-ups across the globe are working to enable Quantum computing.

**Second - What exactly is a Quantum computer and how is it different from our regular (classical) computer?**

The basic difference is Quantum computers use the properties of quantum physics to perform computations. Our regular computers use bits (binary digit) as the basic unit of information. A bit represents a logical state with one of two possible values – generally represented as 1 or 0. In the case of quantum computers, the basic unit of memory is a quantum bit or qubit. Now, what is a Qubit? Getting slightly technical - Qubits are made using physical systems, such as the spin of an electron or the orientation of a photon. These systems can be in many different arrangements all at once, a property known as quantum superposition. Qubits can also be inextricably linked together using a phenomenon called quantum entanglement. The result is that a series of qubits can represent different things simultaneously. Superposition and entanglement allow qubits to be more powerful than classical bits.

For instance, both three bits and qubits will represent 2^3 = 8 states. The difference lies in the fact that classical computers will deal with them one at a time whereas Quantum computers will deal with all states simultaneously. Let's take an example of 64 bits and qubits. In this situation, we will have 2^64 = 1 million terabyte states, and even with the fastest supercomputers (running at 200 million states/second), it will take 100s of years but for Quantum computers it will take a fraction of minutes. This is where quantum computers get their edge over classical computers, i.e., they will help solve problems that are "practically impossible" for classical computers.

**Third - Will Quantum computers replace classical computers?**

The answer is No, they will co-exist. Classical computers will continue to be used for our day to day tasks which do not require huge computational power be it such surfing the web, our day to day office or school or college work, playing games, watching movies, or even basic simulations. Quantum computers will dominate where extensive computing power is needed such as drug discovery, high end engineering calculations and simulations, cybersecurity, weather forecasting, etc.

With the way technology has progressed over last few years, I am very confident that quantum computing will take us to the next levels of computational power. Like with any other emerging technology, there are fundamental challenges that need to be solved and current efforts can be seen as a stepping stone to what is to come. That's where governments, industry, startups and academia need to come together to achieve Quantum evolution. It is how it was done when the classical computer era started, and quantum computing will follow the same but at a much faster pace.