An Introduction to Quantum

5 mins read

The word “quantum” is used as an umbrella term to refer to the emerging field of technologies that harness quantum mechanics to develop fundamentally new capabilities in established fields such as computing, communications, sensing, pharmaceutics, chemistry, and materials research.

In its literal sense, the word “quantum” refers to the smallest unit or entity in a physical system that we describe using quantum mechanics. The reason we physicists have a separate formulation of mechanics for the quantum world is because on the scale of really, really small particles, the rules of classical physics don’t necessarily apply, and we observe strange, new behaviour that we cannot explain with classical physics. Such phenomena include quantum interference and entanglement that allows particles that can be very far apart to be linked to one another.

What is the promise of quantum? Why is it important?

The promise of quantum is to push beyond the boundaries of classical physics by harnessing these quantum mechanical properties of matter. Depending on the context, this can offer entirely new ways of processing information that has the potential to be faster and more resource-efficient, which would enable us to, for example, calculate things we’ve never been able to calculate before, like the formation of proteins or predict the complex behaviour of financial systems.

Where is quantum’s disruptive potential?

There are quite a few areas in which quantum can potentially be disruptive. To just name a few, consider:

  • Optimisation: quantum computers might be able to solve hard optimisation problems much faster and enable us to even solve problems that are completely out of reach today (in terms of the classical computing resources needed).
  • Pharmaceutical/Chemistry research and modelling: quantum simulation can help us understand how molecules and proteins form and lead to breakthroughs in chemistry & biology, drug discovery and healthcare.
  • Cybersecurity: a powerful quantum computer could potentially break existing encryption protocols that rely on factoring large numbers, such as RSA-based encryption protocols. Right now, there is no classical computer or algorithm that can do this within a reasonable amount of time – and so we have the opportunity to develop completely new types of encryption to keep information safe.

What are the benefits of quantum computing? What are the risks associated with this technology?

Quantum computing promises efficiency in processing power. The ability to process information faster opens up the possibility to drive fields such as fundamental research, optimisation, information technology and pharmaceutics to beyond what we ever imagined possible while we had just classical computers.

There are anticipated risks to security.  It is theoretically known that a large-scale quantum computer can crack NSA encryption.  A large outstanding challenge at present is creating security protocols that are secure from both classical and quantum computers.

The unanticipated risks are that there are many yet unimagined applications for a substantially more powerful computer. A quantum computer’s strength is processing Big Data which can have implications on personal privacy.

For example, roughly 1% of the US energy consumption goes into the production of fertiliser. This process is inefficient in part due to the complexity of simulation of the chemical reaction at a quantum mechanical level.  A quantum computer could be used to simulate biological/chemical processes such as nitrogen fixation in nitrogenase thus increasing efficiency in production and leading to a greener approach.

What technical advancements are needed to take quantum computing from a niche existence to the mainstream?

Right now, we are fundamentally limited by the stability of quantum systems over time and our ability to control them accurately. The unique sensitivity of quantum systems to their environment is what makes them so powerful for computing, but it is also what makes them difficult to control with a great degree of accuracy. Because of this, current quantum computers are very small (consisting only tens of quantum bits or qubits – classical computers have hundreds of millions of bits), and the computations we can perform with these small systems are often inaccurate.

To take quantum computing from its niche existence to the mainstream, we need to learn how to isolate quantum systems better from their environment and at the same time how to control them to a much greater degree of accuracy. We need to reduce the errors that we observe in quantum computations and then scale up the system to hundreds of millions of qubits.

How can we overcome these challenges?

We need to overcome the error problem in quantum computations through both innovations in quantum computing hardware and software. More research is needed to understand the error processes that occur in quantum systems and how to build hardware that is more resilient towards those errors. At the same time, advancements in software and how we implement certain algorithms are needed as we hit the physical limits of chip manufacturing capabilities.

How will quantum computing affect/impact the human-technology relationship? How will it impact people’s day-to-day lives?

It’s unlikely that people will have quantum computers at home that replace their classical computers. Rather, think of quantum computers as a research tool that can be used by both researchers and industries. The way it will affect the day-to-day lives of people is through the innovations in the aforementioned sectors.

What trends are emerging with quantum computing? What new developments are on the horizon?

In addition to the state-of-the art quantum computing technologies, there are several proposals for new types of quantum computing hardware such as photonic quantum computers or quantum computers based on neutral atoms that are highly anticipated. Additionally, researchers across the field are working hard on developing algorithms that can boost the performance of noisy, intermediate-scale quantum computers to achieve quantum computing breakthroughs sooner.

What does quantum communications look like?

In practice, most quantum communications look quite similar to their classical counterparts for fibre optic communications. Generally, quantum communications have more stringent requirements on performance and is more susceptible to environmental effects. Therefore, a major challenge is creating secure quantum repeaters to overcome challenges with implementing a quantum network in our everyday lives.

What is the advantage of quantum in communications?

The advantage is secure communications as well as the ability to distribute entanglement.  Entanglement is a quantum mechanical effect that aids into the ability for enhanced calculations and sensing. A quantum network would be able to distribute entanglement so we could create networks of quantum sensors or networks of quantum computers.  Much like how there are CPU clusters for distributed computing we could create a distributed QPU cluster for quantum computation.

Could 7G be quantum?

Unlikely.  Quantum is generally never faster but rather it’s more efficient.  For instance, a classical computer can divide two numbers substantially faster than a quantum computer. It’s only by using quantum efficient subroutines that quantum gets an advantage. Expecting a speed increase by going to quantum is not realistic.

What does the timeline for quantum computing look like?

This is a very difficult question to answer as the problems we are facing today are not certain to have a definite solution. If our research and development efforts continue to be successful, we could conceivably look at a ten year time-scale, however if we encounter new challenges or do not find adequate ways to overcome the error problem in quantum computing, we might actually never get there, and instead refocus our efforts on more achievable goals such as building quantum simulators that solve more targeted problems (as opposed to building general-purpose quantum computers).

What regions of the world does Keysight see as most active in quantum computing?

We are excited to see quantum computing start-ups as well as industry giants such as IBM and Google build up major quantum computing efforts across the world. While the major industry players have their base in North America, more and more engagement can be seen in Europe, Asia, and Oceania. It’s amazing to see that quantum computing has become a global pursuit and we are thrilled to be part of it.

With many companies still looking to generate the intended revenue from disruptive technologies like 5G, AI/ML, cloud, etc., what will be the best time for the implementation of quantum computing?

The revenue potential of quantum computing is complementary to other disruptive technologies and offers potential advancements across a wide variety of fields in industry and research. I believe that as soon as the technology becomes viable it will be successfully implemented and generate vast amounts of revenue for any industry that holds a stake in it.

Author details: General Manager for Quantum Engineering Solutions Elizabeth Ruetsch, at Keysight Technologies