January 4, 2019

Everything you need to know about quantum technologies

We explain everything you might want to know about quantum technologies.

Carly Minsky

14 min read

quantum cryptography

The quantum industry covers far more than just quantum computing, set to be the next generation of super-fast personal and industrial computers. In fact, the broader category of quantum technologies harnesses the strange behaviour of tiny particles for a whole range of applications, including navigation tools, enhanced imaging technology and extremely precise timing devices.

Applications for quantum technologies


One motivation for developing fast, powerful quantum computers is to achieve so-called “quantum supremacy”. This watershed achievement is more than successfully producing quantum computers that are “better” (faster, more powerful) than classical computers; the ultimate goal is to develop quantum computers that can solve very complex problems that are practically unsolvable for classical computers.

For example, the task of determining whether two random number generators are totally mathematically independent has been shown to be too time-consuming for any classical computer to solve in a practical amount of time, but it can be solved by a “very efficient” quantum algorithm. The ability to generate true randomness is extremely valuable for certain computational tasks, particularly in cryptography where random keys are needed, but randomness is in fact very difficult to create. Determining whether two different random sequences of numbers are “secretly” related has significant practical value.


It is generally believed that a device with at least 49 qubits is required to solve problems of this complexity. Although Google announced in 2017 that it was approaching this target, only Intel has tested a chip of this size.

Main players: Google, Microsoft, IBM, Intel, D-Wave, Rigetti

Further reading

  • New software and programming languages are being developed to run on physical and cloud-operated quantum computers. This useful table breaks down which quantum software manufacturers are designing for compatibility with each of the main quantum computer manufacturers.
  • Boston Consulting Group published in-depth report showing the quantum computing ecosystem, funding trends and business predictions.

Strictly speaking, “quantum communication” is actually more like quantum-supported physical communication. The transmittance of information - be it raw data or video calls - still requires the usual physical connections, but the information can be packaged and secured using quantum methods. Quantum techniques can also be used to improve the efficiency and capacity of communication channels. Photonics - the method of using light particles, photons, to transmit or carry information - is a less resource-intensive process, since photons are more accessible than other sources of energy, and fibre cables weigh around 40 times less than cables currently used for telephone lines and broadband internet.

Quantum communication researchers also hope that so-called ‘optical’ communication will support the increasing demand for bandwidth, since it uses a greater range of frequencies than radio waves, for example terahertz frequencies from quantum lasers which would transmit data hundreds of times faster than current wireless networks.

In the UK, academic researchers and a small number of commercial entities use the National Dark Fibre Infrastructure Service - a fibre reserved exclusively for research - to trial quantum communication. A team at University College London used the network to demonstrate that optical communications had the potential to transmit data at 1TB/s – equivalent to sending the complete works of Shakespeare 100,000 times a second.

Further reading

  • Paris researchers have demonstrated that quantum communication is faster than classical communication. This explainer breaks it down.
  • A report by the Institute of Physics maps the “quick wins” and long-term gains from photonics in different industrial applications across the UK.

The most prominent and viable technique within quantum communication is Quantum Key Distribution (QKD). This is a cryptographic method which exploits quantum phenomena like entanglement and indeterminacy to produce and send cryptographic keys securely. Essentially this an evolution of current key-based security protocols already used, but leverages quantum effects to decrease the risk of interception, decryption, hacking and data leakage.

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Main players: The leading specialist in QKD is Swiss startup ID Quantique. Big corporations like IBM and Toshiba also have active QKD research programmes. BT and Toshiba Research Europe are testing photonic technology on the Dark Fibre network in the UK.

Further reading

  • Spanish telecomms infrastructure provider Telefónica has demonstrated QKD on its own fibre infrastructure, with the Munich research lab of Chinese telecomms company Huawei.
Sensors, imaging and measurement

Since quantum effects are extremely sensitive - a quality which actually poses a challenge for quantum computers - they can produce high-precision sensing and imaging tools.

The technology commonly uses single photons for tools like gravity sensors, rotation sensors, magnetic sensors, atomic clocks and imaging.

These tools can then be used for industrial and commercial applications including underground object detection, medical diagnostics, autonomous vehicle sensors, navigation and precise timing for military use.

Main players: In addition to highly specialised startups, like Qnami in Switzerland and QLM Technology in the UK, big companies innovating in this space include Bosch, Honeywell, HP, Microsemi and Texas Instruments.


Further reading

  • Report - Global quantum sensor revenues to reach $1bn by 2023.
Simulation for research and development

As a consequence of progress in quantum computing, there are now opportunities to run virtual simulations instead of physical research and experiments, in sectors like drug discovery, material production and manufacturing.

For complex models where testing involves many different factors - e.g. hundreds of thousands of atoms interacting - running a computationally powerful simulation can lead to faster breakthroughs and an increased volume of research. The complex problems occur across all sectors, including finance and traffic analysis.

Main players: D-Wave, Amgen, Biogen, GTN LTD

Further reading

Target markets for UK quantum technologies industry
Illustration of various sectors in quantum technologies and the different market sizes
Estimated global market sizes from UK government report <a href="">The Quantum Age: technological opportunities</a>

The science

On a tiny particle-level, the world doesn’t behave the way we would expect based on the rules of physics, maths and logic that we observe all around us.In the quantum world, some features of particles are not precisely determined, like position, momentum and spin (angular momentum). This is because on a quantum level, all particles can behave like waves and waves can behave like discrete particles. Quantum systems can behave like both waves and particles at the same time.Just like what we classically understand about waves - which can stretch over more than one precise physical location - quantum particles can be in two (or more) places at once. They can also have peculiar combinations of different momentums and spin states.But the converse is also true; light is typically understood as a wave with wave-like properties (frequency, amplitude), but in fact light waves are made up of discrete particles on a quantum level, called photons. This discovery has enabled researchers to isolate a single light particle which can be used for extremely precise, efficient and fast measurement, imaging and communication.The most ‘spooky’ quantum phenomenon (described as ‘spooky’ by Einstein himself) is that some pairs of particles are ‘entangled’ which means that each particle’s properties instantly react to changes experienced by the other particle, even when the two particles are separated by a large distance and should behave independently. In theory, this effect provides opportunities for instantaneous communication by manipulating one particle to change properties of a second separate particle instantly, no matter how far away it is.More detail: How does quantum computing work?


Cost and resources

To produce quantum phenomena, scientists need to carefully control the environment (i.e. temperature) and manipulate material with extreme precision at tiny scales. The tools to do this - like refrigeration systems and nanotechnology instruments - amount to a huge expense, which presents a significant barrier to entry for quantum technology companies without access to a university or research lab.

“A lot of quantum technologies function at temperatures close to absolute zero, and there is very reliable technology now to get down to these temperatures, called a dilution fridge,” explains Dan Browne, professor of quantum information science at University College London. “It is very reliable technology but they are very expensive - six figure expensive, maybe even seven figures in some cases. They are big investment.

“That is the sort of equipment that is absolutely essential for any sort of solid state quantum technology in order to control the noise and the errors which come from all of the particles in the solid all wanting to interact with each other.”

To meet this challenge and support a nascent quantum technologies startup community, the UK government plans to open ‘Innovation centres’ where small companies can share essential resources, use co-working spaces and collaborate.

The first centre will open in Bristol, and has been described in a university announcement as: “the world's first dedicated open access innovation facility”. Quantum businesses will be able to access 'pay-as-you-go' incubator labs, office space and essential equipment.

According to Dr Jake Kennard, co-founder and head of technical sales at Bristol-based quantum startup KETS Quantum Security, many startup incubators which do offer resource-sharing still fall short even for the more generic and fundamental high-end technical equipment, like electronics for testing and measurement. This hardware - which includes oscilloscopes and pulse pattern generators - is not exclusively relevant to quantum companies, and is widely commercially available, but it will inevitably be too expensive for a bootstrapped startup to buy.

The challenge is greater when it comes to specialised quantum equipment, like photonics tools for creating and measuring low-intensity light.

Kennard says: “You can absolutely buy it off-the-shelf stuff now; there are plenty of startups which sell these peripheral components. But they are a large capital expense for a startup which might not have a lot of money.

“The traditional model is that you share this equipment among people in the same building with similar needs, but that just doesn’t exist for quantum startups.”

Main player: Oxford Instruments is a leading European provider of technology infrastructure for quantum innovation.

Further reading:

Pitching for the future

Return on investment is particularly hard to predict for quantum products. Many ‘blue-sky’ products are a long way from market-readiness, and for some technologies, the true value of the product depends on the advance of quantum technology in other areas.

For example, quantum software products become extremely valuable only after the proliferation of quantum computers; post-quantum cryptography becomes more valuable as quantum computing power increases.

Further reading:

  • Founder of UK startup Post-Quantum discusses his difficulties raising investment.
Infrastructure transition

In some cases deploying quantum technologies at scale requires a significant overhaul of the existing core infrastructure. Examples include timing and navigation systems, communication networks, and internet security protocols.

Even though quantum technologies provide significant opportunities for improving these core systems, the interim period as new technologies are developed, tested and implemented also presents new risks, like unreliable timing services during a transition from satellites to atomic clocks.

The challenge is to reliably manage and mitigate these risks preemptively, even risks from yet-to-be deployed technologies or yet-to-be-developed technologies. Decisions have to be made now with respect to protecting and improving core infrastructure, like internet security, without understanding the standards that new technology needs to meet and without any reliable information on how long those standards will remain appropriate.

KET Quantum Security’s Jake Kennard worries about this with respect to quantum encryption.

“The reality is that we have got a big upcoming problem around quantum security - this threat of a quantum computer being able to break security everywhere. There is a subtlety around it, which is that it takes time to upgrade infrastructure.

“It’s a problem around data lifetime. If i am a company sending intellectual property and it is encrypted, a hacker can store that and just wait until a quantum computer comes along. Depending on the lifetime of your data, and there are other examples in military and government applications, that deadline is already past for infrastructure upgrades.”

Further reading:

  • A report by the UK government addresses infrastructure challenges and opportunities arising from quantum technologies.
Technology at scale

Much of the quantum technologies work now is to scale-up or improve quantum technologies to create useful commercial products.

To create useful commercial products, each quantum subsector has to overcome particular limits:

  • Quantum computing has yet to reach large-scale processing power due to decoherence - when quantum systems interact with the external environment and quantum effects are lost.
  • Quantum communication has yet to cover large distances in a way that is efficient and scalable
  • Quantum simulation produces results which are hard to validate and verify
  • Quantum sensing is still subject to quantum noise - errors resulting from quantum uncertainty - due to the high-sensitivity of the technology, and optical losses - reductions in the light intensity due to photon interactions - which reduce reliability.

Further reading:

  • This article opens with a neat summary of computing computing hardware challenges
  • A very technical paper proposes new methods for managing quantum sensing in practice

From the experts

Excerpts from the European Quantum Technologies Roadmap, written by researchers working in specific areas of quantum technologies:

Quantum technology startups in Europe