The design of computers since Babbage in the 1830s, until they became commercially available in the 80s, was done with the ideology that atoms existed as particles (electrons) and stayed in orbits that rotated around a nucleus. It was also assumed that every particle had a defined position in time so only two positions were maintained. A particle was either in a location or it was not. Logic gates had OFF/ON states and computers were programmed to read characters in binary states recognised as ‘0s’ and ‘1s’, stored as bits, and are what we now know as ‘classical’ computers. 

With this, computers could take in information, process it, and give an output based on programmed parameters. Over the years, these computers through their processors have been able to solve numerous problems by a sequencing approach of following the algorithms one step at a time until they uncover the full problem and have been used to develop complex solutions to incredibly hard problems.

However, as the world evolves, so do our problems. Today, we have even more complex challenges and our understanding of the universe has improved with the realisation that atoms can exist as both particles and waves. Also, we now understand that particles can exist in multiple quantum states at the same time.

In some instances this has led to the breaking point of computing as we know it especially when trying to make incredibly complex computations. Classical computing is slow in processing these complex problems and now, more than ever, there is a need for a new type of computing to solve the complex problems of chemistry, mathematics and the universe itself. This is where quantum computing may play a huge role since it is derived from quantum physics which explains the duality of matter and the existence of atoms in distinct energy states.

What is Quantum Computing?

Quantum computing is the application of quantum mechanical theories in technology to solve complex problems (defined as problems with multi-dimensional variables) and have information stored as quantum bits or qubits. 

Theories such as the existence of the wave-particle duality of matter which means that matter can behave as a particle and wave based on certain conditions, or the one-dimensional and three-dimensional position of matter in a wave equation and its existence in multiple states known as superposition, or the uncertainty principle stating that the position and speed of matter cannot be known with exact accuracy and many more advanced theories have been adopted into technology to give output to problems in a dynamic way. 

Typically, computers are designed to have processors that enable them to solve problems at incredible speed but they still falter in the face of high-complexity problems. This is a result of the binary-coded structures of the computers and supercomputers of today. So, since they exist in binary form, they can only be optimized to meet the ever-changing demand for great solutions but will never be hyper-efficient for the complexity of all of the future problems we face. Quantum computing has great potential to solve these problems, easily and at a speed never seen before.

This is why quantum computing is gaining popularity, especially among scientists and engineers as it can be a bedrock of future and emerging technologies such as artificial intelligence as it gains global acceptance.

Features and capabilities of a quantum computer

A quantum computer is by its nature complex. It comprises both hardware and software just like any computer. The hardware combines quantum data planes that house the qubits and all structures, measurement planes where all measurements on the qubits are made, quantum processors for sequencing operations and measurements, and a host processor, a classical computer for connecting to large network arrays and user interfaces. The software for operating a quantum computer requires a quantum programming language (examples include Q#, Quipper, QuiCK etc.) for writing algorithms, quantum compilers/processors to analyse and map to the hardware, and support tools for debugging, testing, and optimising the system for optimal functions.

For these features to work optimally, certain capabilities of quantum computers are required to enable them to solve problems at a rather complex level. 

Superconductivity is one of such. Superconductivity is a phenomenon that allows electrons to flow freely in a conductor without any form of resistance. It is achieved by placing the conductor (the material that allows the passage of electrons) at very low temperatures so that they can retain quantum states so that electrons do not jump from one energy level to the other. So, even though electrons flow freely, the materials have a unified energy level maintained over a while to allow certain computations to occur quickly. This creates a computational state within the superconductor. Quantum processors are designed to achieve superconductivity so they can carry out sequencing functions within a short timeframe.

Imagine being able to be in multiple locations at the same time. In quantum mechanics, electrons behaving like waves can maintain multiple states at a given time until they are measured. This concept is known as superposition. With superposition, characters that originally would be either 0 or 1, can be both 0 and 1 meaning that their complex behaviors can be observed using quantum computers. The possibility of this happening at scale can open us to a way of observing everything within our universe and propel the development of accurate and efficient solutions to problems.

Another capability of quantum computers is quantum interference. Interference generally occurs when two waves collide to form a bigger wave when the troughs and crests are in sync or cancel out when the troughs and crests meet at a point. Now, when it occurs at subatomic levels where particles interact with themselves or other particles within multiple probabilistic quantum states, it is said to be quantum interference. Quantum computers can perform complex calculations when many variables at multiple states interact with themselves and others simultaneously, to give a probable outcome with a high degree of accuracy rather than performing a sequence of actions one variable after the other to give an outcome seen in classical computers. This, therefore, is one of the major reasons for the speed associated with quantum computers.

Exploratory applications of quantum computing

Although quantum computing is not yet generally available for wide commercial usage, there has been tremendous progress in its application across various industries. Companies such as IBM, Microsoft, Google, and Amazon are at the forefront of the development of quantum computing technologies to tackle global problems. Some of the interesting applications include:

1. Chemical Simulation: Simulating the chemical reactions in batteries for electric vehicles. This is a combined research between IBM and Mercedes Benz to not just understand the workings of batteries but their interactions at sub-atomic levels which could reduce the time of production for batteries that would power the future of electric vehicles which is a major focus for Mercedes. Using supercomputers for these simulations slows the process with estimated results filled with assumptions. With quantum computers, it is becoming possible to understand how the electrons in batteries interact for optimal performance.

   
   
   

2. Weather Forecasting: Regetti Computing is exploring the application of quantum computing in accurately predicting weather conditions in a faster and more efficient way. It is betting on the quantum interference capability of handling complex variables simultaneously rather than sequentially. With its Novera 9-Qubit QPU Quantum Computer, organizations can now solve even more problems as it has 99.9% fidelity.

   
   
   

3. Pharmaceuticals Development: Quantum computing is currently being explored in the design of drugs for the pharmaceutical industry. This publication outlines the opportunities and challenges involved with this process and how quantum computing could transform industrial research in drug discovery and design. 

   
   
   

4. Algorithmic Trading: Amazon Web Services have designed a quantum computer known as Amazon Braket. This service was used by the Fidelity Center for Applied Technology to experiment with option pricing for stocks with synthetic yields on various quantum computing technologies. They discovered that the platform was quite flexible in understanding the strengths and weaknesses of different quantum computing technologies.
   
   

There are many more applications of quantum computing and various research institutions and commercial organisations are actively developing solutions in this space to tackle challenges across various industries. Eventually, when error pruning is achieved, commercialisation will change how solutions are built in the future.

Why quantum computing may be the future

We have discussed quantum computing and how it can easily speed up problem-solving processes for complex computational challenges. Today, supercomputers are the best options in the market for complex calculations, but the challenges posed are quite enormous for certain types of mathematical problems, such as chemical simulation,  leaving an opportunity for the rapid development of quantum computers. As with most new technologies, quantum computing is not quite yet commercially viable as they are expensive and have high error rates. We, however, expect that this will soon be history and a new world of computing will emerge and within the next ten years humanity will be firmly rooted in the quantum age.

As more organisations find solutions to wicked problems such as global warming, decarbonisation of the environment, clean energy generation, mine cleansing, and so on, quantum computing may truly be the future of computing. The question that should then be asked is when is it likely to be available to the public for general usage? How will it affect our daily usage of computing? How will it integrate with artificial intelligence and what outcomes will be drawn out of it? These are questions that time will tell but with the massive investment and focus in Quantum computing we do hope that it is not so distant.