Quantum computing has the capacity to change our future. It has the potential to completely transform medicine, break high level encryption and speed up artificial intelligence. There is currently a race on, between IBM, Google, and Microsoft to build the most reliable quantum computer that can significantly outperform any modern-day supercomputer. It has now become a billion-dollar race, with each company claimed to outperform each other, china has invested billions into quantum computing. But what is quantum computing? Are we going to see everyday desktops running on this technology? How does it actually work?
What is Quantum Computing?
A quantum computer is just like any other computer that performs complex calculations; however, it uses quantum mechanics principles to perform these calculations at very high speeds. A traditional computer uses bits, which stores information as binary 1’s and 0’s, these are just like tiny switches that turn on (1) and off (0). On our everyday computer we use apps, website, videos, and images which are made up of millions of bits and are translated into what we see and hear on our computers.
This theory of using bits works well for most things and our computers can easily calculate these outcomes in 1’s and 0’s. However, we know that there are also instances of uncertainty which requires extraordinarily complex calculations, just like nature and the universe. Our computers cannot deal with this uncertainty, even super computers have some trouble with these calculations taking many years to perform a complex calculation.
In 1927 a German physicist Werner Heisenberg introduced the uncertainty principle, which states that you cannot know everything about a quantum particle at the same time. The more you know about its position, the less you know about its momentum. This became known as quantum mechanics.
A quantum computer is using the principles of quantum mechanics by taking those 1’s and 0’s and adding an uncertainty to it so it can be either a 1 or a 0 at the same time. For example, if you flip a coin and it lands on heads this could be a 1, if you flip the coin again it could land on tails and this could be a 0. So, every time you flip the coin you will have a certain outcome. What happens if continually spin the coin? Is it a 1 or a 0? It is both. This state of uncertainty is known as super position in quantum computing and is the same as spinning the coin. The more super positions you have in a quantum computer the more combinations and more memory you can have.
How do Quantum computers work?
Instead of using bits like normal computers, quantum computers use something called qubits. Qubits are made of super conducting materials and are a physical device. Qubits are controlled using microwave pulses which have been specified with a particular frequency and duration to put the qubit into a super position or will flip the state to one way or another. Because each qubit represents two states at once, the total number of states doubles with each added qubit. One qubit is two numbers, two is four numbers, three is eight and so forth. It starts low but gets huge fast.
Qubits are small, all the way down to molecular level. Therefore, qubits are mostly made from electrons because of the quantum mechanic properties, in particular their magnetic field property. This is why they serve as a fundamental building block in a quantum computer. For an electron to be used as a qubit, there must be a reliable way to determine its position and switch its direction. Qubits use a concept known as a quantum dot, which is a spherical volume typically with a diameter of one tenth of a thousandth of a millimetre. Inside this quantum dot, which is made from two semiconducting materials such as silicon and germanium cooled to exceptionally low temperatures, is a free electron. In this format, the electronic spin can be switched electronically.
Super position – As we have already explained, super position is the uncertainty of the state of a qubit where it can be on and off at the same time or somewhere on a spectrum in-between the two. A good example of how this works is if you ask a normal computer to enter a maze and find the exit it will try every single route, ruling them all out using trial and error until it finds its way out of the maze. This process can take a long time as well as take up more memory to store each failed route. Ask a quantum computer to find its way out of a maze and it will go down every single path within the maze at the same time. It can have that uncertainty. Combined with entanglement and interference which are the two other elements of a quantum computing and it can find the exit in the maze in an instant.
Entanglement – Qubits can also do something called entanglement. Going back to the coin toss analogy, if you flip two coins the result of one-coin toss has no influence on the other, they are completely independent to one another. In entanglement, two particles are linked together even if they are physically disconnected to each other. This entanglement means if you flip both coins at the same time, the result is also the same. They behave in ways which becomes a sort of system. Entanglement is used to reduce the number of errors in a system whilst performing more efficiently, achieving calculations much quicker.
Interference – By using a quantum property such as interference you can control the quantum states by amplifying the signals that are more towards the correct answer and cancel the types of signals which are leaning towards the incorrect answer. This works remarkably like how noise cancelling headphones work which reads ambient wave lengths and then creates the opposite wave to cancel it out by creating interference. As we know you can constructive interference and deconstructive interference. Constructive interference amplifies the wavelength, so the signal gets larger and if you have deconstructive interference the amplitude gets weaker. This works the same in quantum computing, allowing to control the states.
The combination of all three of these elements is what makes a quantum computers work, to perform complex calculations and extremely high speeds.
What are the challenges in Quantum computing?
Quantum computing is very much still at its infancy but there is a lot of great research being done to open its capabilities further. One of the greatest myths revolving around quantum computing is simply adding more qubits will increase its capacity. Whilst that is true, it is also one of the greatest challenges in quantum computing as it is not just that simple. Quantum computers are extraordinarily complex machines with its high precision microwaves and sub-zero temperatures, they are extremely sensitive to any electrical noise or environmental effects. When you add another qubit you are effectively multiplying the problems.
Another challenge that some people find hard to grasp is that you can only hold the quantum information for so long. There are only so many calculations that can be performed before you start losing that information.
What are the next steps?
What needs to happen now? The current industry leaders need to start building abstract layers to make it easier for programmers and scientist to just come in and start learning, researching, and finding new areas of applications for quantum computing. This will also require the development of new quantum algorithms that research partners are working on. Progression will also go together with the exponential growth of the hardware and the quantum processors, adding more qubits.
Who is using this technology?
Quantum computing has the potential to rapidly accelerate artificial intelligence and Industry 4.0. Google is already using them to improve self-driving cars as well as modelling complex chemical reactions.
Here is a comprehensive list of the most popular quantum computing applications:
- Drug development
- Financial modelling
- Better batteries
- Cleaner fertilisation
- Traffic optimisation
- Weather forecasting and climate change
- Artificial intelligence
- Solar capture
- Electronics materials discovery
Daimler AG – In 2018, German car manufacturer Daimler AG announced two partnerships with Google and IBM. Electric vehicles are fundamentally based on battery cell chemistry. Quantum computing adds hope for areas like cellular simulation and the aging of battery cells. Improved batteries for electric vehicles could help increase adoption of those vehicles.
Daimler is also looking into how quantum computing could potentially accelerate AI, as well as manage an autonomous-vehicle future and accelerate its logistic network. It follows in the footsteps of Volkswagen. In 2017, VW announced a partnership with Google focused on similar initiatives. It also teamed up with D-Wave Systems, in 2018.
Volkswagen Group – D-Wave and VW have already run pilot programs on a number of traffic- and travel-related optimization challenges, including streamlining traffic flows in Beijing, Barcelona and, just this month, Lisbon. For the latter, a fleet of buses travelled along distinct routes that were tailored to real-time traffic conditions through a quantum algorithm, which VW continues to tweak after each trial run. According to D-Wave CEO Vern Brownell, the company’s pilot “brings us closer than ever to realizing true, practical quantum computing.”
JP Morgan Chase – It is no surprise that one of the largest financial companies is interested in quantum computing. After all the financial market is an uncertainty in some respects. JP Morgan is one of the partners of Microsoft’s quantum network which includes research universities, tech companies and business affiliates. Quantum computing and financial modelling are a match made in heaven, having many structural similarities. Now research has been done on the Monte Carlo model, which gauges the probability of various outcomes and assess their risks.
What are the most innovative things happening in Quantum computing?
Most of the big break through things that have happened so far have come from controlled settings, where they are using problems that they already know the answers, to achieve quantum supremacy. Google recently claimed to have already achieved quantum supremacy, which is where a quantum computer outperforms a traditional computer. Google says that its 54 qubit processor was able to perform a calculation in 200 seconds that would have normally taken a traditional computer 10,000 years. This claim was also heavily criticised by IBM, which says the calculation would have only taken 2.5 days.
Researches have also been working on creating algorithms such as Shor or Grover algorithms that quantum computers will use but the devices themselves still need a lot more work. It is now expected that the innovation will grow, increasing exponentially with computational value, and hardware improvements which is expected to grow every 4 years based on the quantum equivalent to Moore’s law. The goal would be to have the volume to run the desired quantum algorithms. When this occurs, the focus will then be on quantum error correction.
A quantum computer is designed for use in high numbers of complex calculations that needs a fast response. It is not and will not ever be used to replace our traditional computers we use every day. The applications we use daily such as watching HD videos, browsing the internet and word processing will not bring any advantages in quantum computing. You can see the enormous potential in this technology, and it is already gaining a lot of momentum with large companies investing millions. The future is exciting, and this is an area to keep a watch on.