What is Quantum computing? The supercomputers of the future
IONOS editorial team8 mins
Quantum computing is meant to revolutionise computer technologies by using quantum mechanics. Principles such as superposition and quantum entanglement are to be used alongside qubits in quantum computers. This will enable them to perform high-performance calculations with almost limitless processing power. Whether quantum computers become a thing or not all depends on us getting over technological hurdles such as the entanglement of qubits and modern cooling systems.
What is quantum computing?
There’s something new being talked about in the computing world – something that goes by the name of quantum computing. If all expectations become reality and quantum computers find themselves on the market, it will be nothing less than a technological revolution. How is this meant to work though? Put simply, by using the laws of quantum mechanics. Among these include three principles which can be seen as the pillars of quantum computing:
- Superposition: This is the ability of a quantum system, to take on multiple states at the same time, 1 and 0 instead of 1 or 0.
- Quantum entanglement: This is a phenomenon seen in quantum mechanics at which two or more smaller parts are entangled with each other and create an entirely connected system. Changes to one of the smaller parts in the entangled system will automatically affect all the parts it’s connected to.
- Quantum collapse: This is the point at which systems are measured and go into a defined state, from 1 and 0 to 1 or 0.
Our standard computers are based on the binary, electrical principle of ‘on/off’ or ‘1/0’. On the other hand, quantum computers use non-binary, multi-dimensional and quantum mechanical states. Unlike our classic computers, they don’t solve problems one after the other, instead, they do everything at the same time, including complex entries. By doing so, they should be able to create a million times more processing power and provide a significant reduction in the time needed to perform calculations.
If everything goes to plan, quantum computers will be a technological leap forward and will be noticed in all areas of complex data processing. This will include, among other things e-commerce, cryptography, medicine and financial transactions as well as big data, artificial intelligence and machine learning.
How does quantum computing work?
It’s not easy to understand quantum computing. Instead of using binary bits, quantum computers use qubits (quantum bits) to solve mathematical problems and to prepare datasets. The traditional bit is based on binary code.
A bit can have only one of two states: 1 or 0. Qubits, on the other hand, are non-binary and can have both states at the same time: 1 and 0. This quantum mechanical approach increases the performance potential of quantum computers compared to binary PCs by a million times. This is because qubits not only have the 1 and 0 states at the same time, but they can also assume an infinite number of intermediate states. Since quantum computers can process more than one piece of information at the same time, they are able to solve complex tasks, which would be impossible for standard computers.
Superposition and quantum entanglement
Let’s take a simple example: Image the functions of a standard computer and a quantum computer as if you were flipping a coin. Classic computers will direct the coin to land. They will only be able to understand one of two states, heads (0) or tails (1). A quantum computer, on the other hand, ensures the coin never lands, keeping it permanently suspended and giving heads and tails at the same time. This is what’s known as a superposition.
Only when taking a reading do qubits accept a binary state. Now, imagine the floating coin again. As long as nobody is looking at the coin, it’s constantly between heads and tails. If it’s looked at or a reading is taken, then it falls to the floor giving heads or tails. What’s more, qubits are entangled with each other in quantum computers. If a qubit is changed, then all the others connected to it are changed via quantum entanglement. This also allows the calculation speed of quantum computers to be improved. More qubits are then included in a quantum register made up of binary bits for processing.
How much more power do quantum computers have?
Science and industry have great hopes for the power of quantum computers. Some scientists even expect that by using them they would be able to simulate the Big Bang and find evidence for parallel universes. It’s certain that despite the technical challenges, quantum computers could have unlimited potential. This is because a qubit has more than double the processing power of a bit since it can accept the states of 1 and 0 and numerous states in between. With every additional qubit, the processing power is then further increased. Three qubits could accept 8 states at a time, 300 qubits could accept two times 300 states.
What are the pros and cons of quantum computing?
| Pros | Cons |
|---|---|
| Improved processing power and calculation times even with large, complex datasets | Technical challenges with regard to cooling and entanglement of bits |
| Can process a large number of entry values carried out at the same time, not linear | Requires a change of direction and new digital infrastructure since quantum computers are based on different principles to classic PCs |
| Promotes the further development of artificial intelligence and machine learning | The power could be dangerous in the wrong hands |
| Improves medical research since quantum computers can exactly simulate molecules and genes as well as process big data | Calculations cover a wide range of results and in certain circumstances could be less precise than binary computers |
| With prime factorisation they offer unlimited potential for highly secure encryption processes |
Possible use areas for quantum computing
It will be some years yet before quantum computers find a use in day-to-day life. However, we can still imagine them being used in the following areas due to their advantages when using complex data systems and processing:
- Quantum simulations for science and medicine
- Quantum chemistry and biology
- Creating complex financial models
- Optimisation of artificial intelligence and self-learning systems
- Optimisation of encryption technologies in cryptography
- In smart tech such as smart grids, cities and houses
- Automated driving
- Data mining
- Air travel
Technical hurdles for quantum computers
The main reasons why quantum computers are still in development are the technical challenges. This is because qubits are a very sensitive and volatile quantum system. To the most precise results, quantum computers must be able to entangle millions of qubits with each other in a reliable way. And another thing: Quantum computers can only work properly at absolute zero (-273.15 degrees Celsius). Currently, it takes days and a highly modern cooling system to cool modern quantum chips.
Quantum algorithms work on a completely different basis from known algorithms when solving complex problems and to process data. This means creating multi-dimensional processing and storage units as well as simulation rooms, which today’s computers can’t do. For this reason, new hardware and software will be needed for quantum computers, in order to copy and process the datasets to be used in qubits. Programming and programming languages will have to change to meet the principles of quantum mechanics.
Where is quantum computing today?
Quantum computing was first mentioned in 1980 by the physicist Paul Benioff when he described a quantum-mechanical version of Alan Turing’s computer. The theoretical physicist Richard Feynman and the mathematician Yuri Manin then later calculated the power of quantum computers compared to standard computers in the late 1980s. Since then, interest in quantum computing has grown considerably. A good example of this is that governments as well as companies such as IBM, Google and Microsoft have been working hard to make quantum computing work, investing millions in research.
In 2019, IBM released a quantum computer with 20 qubits. Then on October 23, 2019, Google announced the arrival of ‘Quantum supremacy’ and the Sycamore chip following a cooperation between Google AI and NASA. Sycamore is reported to have been able to solve problems which even the best standard computers were unable to solve. In 2020, IBM then claimed to have developed a quantum computer by the name of ‘Hummingbird’ with 65 qubits. In 2021, they followed this with a 127-qubit computer named ‘Eagle’.
At the beginning of 2023, another major problem of quantum computing was solved: how to transfer quantum computing data efficiently and consistently between two chips. Previously it had been a challenge, but now it is possible to achieve a success rate of up to 99.999993% when transferring data from one chip to another.
Despite the constant development of supercomputers, we can’t expect them to replace standard computers at the moment. Instead, it is expected that we will see a hybrid approach with a combination of standard PCs and quantum computers. This comes with the advantage that quantum computers can process massive amounts of data to deliver initial results and the current, more precise supercomputers will be able to work on the binary principle.
