Its market value will soon be measured in billions, yet quantum computing has yet to reach a marketable state and don’t expect it to replace classic computers, says Scott Jordan. So what’s all the fuss about?
Quantum computing has received a tremendous amount of attention in the past decade and, although this technology is still far from being commercially viable, it has shown a great deal of promise in solving complex problems that classic computers are struggling with. As with any new and developing technology, there is currently no universal way to implement a quantum computer, and a wide range of approaches are being pursued – from quantum dots to trapped ions and superconducting circuits.
According to a recent report, the global quantum computing market is valued at $866 million in 2023 and is expected to reach $4.4 billion by 2028, growing at a compound annual growth rate of around 38.3% in this time [1].
The market growth is being fuelled by increasing investments from governments and private organisations, as well as the rising number of partnerships and collaborations between quantum computing companies and end-users. Big names such as Google, IBM, Microsoft and Honeywell are making signifi cant advances in developing quantum algorithms and applications, but there is still a way to go until the technology reaches the mainstream.
Renowned physicist and Nobel laureate Richard Feynman once said: “I think I can safely say that nobody really understands quantum mechanics,” but understanding the detailed theory is not essential for those looking to explore this new technology. While getting to grips with exactly how a quantum computer functions may be beyond many of us, understanding its function as an advanced computer may be enough to start.
From bits to qubits
There are some similarities between quantum and classical computers, as both need means to store and process data, but there are also fundamental differences.
Classic computers use bits, performing computations in a binary language of 1s and 0s – known as states – represented by the presence or absence of current through a transistor. The connection of states allows computation and logic.
Quantum computers, on the other hand, follow different rules. They are based on the interactions of tiny particles such as atoms, electrons and photons. As the scale decreases, classical physics breaks down, and binary states can no longer be applied. The basic element of the quantum computer is the quantum bit – called a qubit – that can be either zero, one or a superposition of the two states. In other words, a qubit can be in an infinite number of states until it is measured. The pre-readout mix of states is representative of probability.
While quantum computing is still a relatively new field, and is not yet widely available for general use, it has the potential to revolutionise fields such as cryptography, materials science and drug discovery, among others
Like in classical computers, qubits can be connected, although this time through a property known as entanglement. This entanglement can be leveraged to perform computation and logic, making it possible for quantum computers to perform certain tasks – such as encryption, optimisation and data analysis – a lot faster. At the same time, it is important to be aware that quantum computers will never be able to solve some problems that classical computers manage easily, and some experts therefore believe that the computers of the future will be hybrids, taking the best from both worlds.
Qubit candidates
The physical implementation of a qubit can be based on any particle that is small enough to exhibit quantum properties and has two distinct states that are possible to measure. For example, a supercooled trapped ion can be in two energy levels and is held fixed by an electromagnetic field supplied by two laser beams. Other possibilities are cavity quantum electrodynamics (QED), photonic circuits, silicon quantum dots and superconducting circuits.
The latter is one of the most promising approaches, as it made it possible to create devices with up to 72 qubits. Many of the current quantum computers must operate in cryogenic chambers at very low temperatures, in the millikelvin range. Interestingly, photonic circuits are now being developed that can operate at room temperature, representing a major step forward in practicality for these systems.
The challenge of alignment
Working with the small features necessary for quantum computing requires extreme positioning control; the optical fibres used to transfer signals to and from qubits must be perfectly aligned, which becomes especially complex when there are several channels. Specialist equipment – such as Physik Instrumente’s ultra-precise piezo nanopositioners, motorised stages and hexapod microrobots – will be important tools to allow the development of quantum computers that can achieve simultaneous alignment of inputs and outputs across several channels, and over multiple degrees of freedom.
Making the quantum computer leap
The quantum computing market has enormous potential for growth and innovation. It is expected to grow rapidly in the coming years, driven by the increasing demand for faster and more powerful computing capabilities across various industries. While quantum computing is still a relatively new field, and is not yet widely available for general use, it has the potential to revolutionise fields such as cryptography, materials science and drug discovery, among others. Developing tools to handle the intricacy and tiny scale of quantum computer chips will be vital for the technology to continue to evolve.
Scott Jordan is Head of Photonics and Senior Director of NanoAutomation at Physik Instrumente Quantum of challenge
References:
1 Quantum Computing Market by Offering, Deployment (on-Premises and Cloud), Application (Optimization, Simulation, Machine Learning), Technology (Trapped Ions, Quantum Annealing, Superconducting Qubits), End User and Region- Global Forecast to 2028. Markets and Markets, March 2023
