Businesses can benefit from quantum computing without waiting for millions of qubitsCredit: hh5800/ Getty Images
When quantum computing makes headlines, it’s typically one of two stories.
The first is a promise: incredible power is coming. Engineering marvels from Silicon Valley or China, boasting quantum bits in record numbers, and delivering genuine, real-world quantum computation, are just around the corner.
The second is a warning: quantum computers will put the world’s data at risk. Many tech and communication companies are switching to so-called post-quantum cryptography in a push to mitigate this looming security threat.
With the discussion so future-focused, it’s easy to miss profound developments already underway: quantum tech start-ups and scale-ups are rapidly moving quantum computing from R&D to industry boardrooms, demonstrating tangible value for business and industry, today.
As Markus Pflitsch, founder and CEO of Swiss-German firm Terra Quantum, puts it: “We have entered the era of quantum as a service.”
Hybrid computing: the best of both worlds
While Big Tech companies set timelines for processors with thousands or even millions of qubits, the timeline for quantum computing at that scale remains debated. Given that today’s commercial processors range anywhere from a dozen qubits to a thousand, talking about quantum as a service in 2024 may seem premature. “Quantum computing is rapidly evolving, but the hardware isn’t there yet,” Pflitsch acknowledges. “These chips are nice for toy problems, but they don’t unlock real business performance by themselves.”
Terra Quantum is focused on hybrid computing, which combines high-performance classical computation with available quantum processors, playing each to its strength. For certain applications, hybrid algorithms have already shown tantalizing performance boosts over their conventional counterparts1.
For example, the advantages of hybrid systems become evident in artificial neural networks or deep-learning algorithms used in image recognition, drug design and other tasks. During training, these neural networks perform difficult, multi-layered optimization, consuming vast computational resources.
“In image classification, for example, the most complex part of such artificial neural networks may often be the final layer, through which the classification happens,” explains Florian Neukart, Terra Quantum’s chief product officer. “This can be expressed as a quantum circuit and is thus efficiently solvable with quantum processors.”
Through Terra Quantum’s cloud-based hybrid platform, powerful conventional computers do most of the work, strategically handing calculations to quantum processors as needed2.
“With just a few qubits,” Neukart observes, “we achieve better performance over classical algorithms in speed and accuracy.”
Simulated chips, real gains
Terra Quantum's hybrid algorithms outperform classical ones without physical qubits, by using simulated quantum processors3.
“Chemists simulate molecular configurations or chemical reactions on conventional computers by mimicking quantum behaviour with classical algorithms,” Neukart explains. “Simulated qubits extend this concept to observing the behaviour of entire quantum chips, rather than just single particles.”
For many applications, whether using actual qubits or quantum logic on simulated qubits, the fundamental nature of quantum algorithms, and the benefits they yield, is the same. “You could ask, why use physical qubits at all?” says Neukart. “Why not simulate a quantum processor as big as you want?”
The answer is that simulation requires a lot of hardware: adding one qubit doubles the computational and memory requirements. “We can't do that indefinitely,” says Neukart. “For more complex problems, we need physical quantum chips.”
For now, adds Pflitsch, Terra Quantum’s algorithms can run on either real or simulated quantum processors. More powerful quantum processors can be seamlessly swapped in as they arrive. “That’s critical for industry value. As chips scale up, the customer’s software automatically becomes more powerful.”
Record-breaking security
Data security is central to Terra Quantum’s offering, and Neukart stresses the difference between post-quantum cryptography approaches and Terra Quantum’s protocols.
“Post-quantum cryptography uses classical algorithms,” he explains. “They are currently resistant to quantum attacks, but it’s possible a future quantum computer may break those algorithms.”
The only technology that is fully trustworthy, Neukart contends, is quantum key distribution (QKD). Its security derives from the fundamental property that measuring a quantum system necessarily disturbs that system — enabling detection of eavesdroppers by monitoring changes in quantum states. Upon detection, encryption key transmission halts, safeguarding sensitive data.
In May 2023, Terra Quantum introduced a novel QKD protocol4 based not on the mathematically complex codes used in traditional protocols, but on the second law of thermodynamics following from quantum irreversibility5, led by Valerii Vinokur, Terra Quantum’s chief technology officer.
“We considered a simple quantum mechanical model to explain where irreversibility in nature comes from,” says Vinokur. “When a quantum state is measured, it ‘collapses’ to one of the possible outcomes, and the process can't be reversed to obtain the state before measurement.“ This property is crucial for QKD security: any eavesdropping attempt, which necessitates measurement, will alter the signal in a detectable way. “We checked our hypothesis experimentally, and it all worked excellently.”
Vinokur’s results introduced a powerful new practical approach to secure communication: a protocol to allow control of signal loss and extend the safe communications channel over long distances.
“Our new QKD protocol, relying on physical transmission line control, swiftly detects eavesdropping attempts and minimizes intercepted coherent photons,” explains Vinokur. “Therefore, thwarting the eavesdropper's decryption attempt.”
Pflitsch emphasizes this isn’t pure theory: Terra Quantum has tested its protocol experimentally as described in a preprint6, and been able to send QKD-secure signals over a record distance of 1,079 km, at data rates orders of magnitude higher than is allowed by previous techniques.
Quietly quantum
Pflitsch founded Terra Quantum in 2019 and describes it today as one of the largest and fastest-growing quantum tech companies. With clients in automotive, healthcare, energy and finance — any company with complex networks, supply chains or digital security — the company covers most industries.
“Our services enhance productivity and profitability — crucially, without the need for our clients to build expertise in-house. They don’t need their own physicists,” Pflitsch explains. Terra Quantum provides infrastructure, software and easy-to-use APIs, deployed through the cloud. “We really lower the entry barrier to quantum for industry.”
Pflitsch believes it is vital to demonstrate to businesses the real performance gains from quantum services. It’s also why he wants to shift the discussion, de-emphasizing the quantum and highlighting services.
“Initially, we said to corporate leaders, ‘We do great things in quantum, you should listen to us.’ That got us into their innovation departments,” says Pflitsch. “But that’s not where we want to be.”
Instead, Pflitsch wants to talk to the people who have business problems to solve.
“These days, we tend to hide our passion for quantum,” Pflitsch concedes. “We’re a business performance-enhancement company first: we help you solve your problem. And we use quantum, but you don’t have to care. That’s our job.”