Quantum computing gets a lot of attention as its speeds toward commercialization, but quantum sensors have also made gains with potential across a diverse range of use cases.

In a recent report, research firm IDTechEx explored the future of the emerging quantum sensor market, projecting that it will reach US$2.2B by 2045 with a CAGR of 11.4%, in part due to “growing hype and synergistic development with other quantum technologies.” The research firm predicts growth in quantum computing and communications will help to drive interest and investment into the quantum sensor space.

The defining characteristic of a quantum sensor that sets it apart from other sensors such as radar and lidar is its sensitivity, thus enabling it to measure a wide range of physical properties including electric and magnetic fields, current, gravity, linear and angular acceleration, and light, among others.

In an interview with Fierce Electronics, Noah El Alami, technology analyst at IDTechEx, said the properties of quantum sensors make them suitable for a wide range of applications, including electric vehicles, GPS denied navigation, medical imaging, communications, and quantum computing, as quantum sensors such as magnetometers and single photon detectors will enable the scale-up of quantum computers as their complexity and qubit numbers increase.

Unlike quantum computing, which is at least five years away from commercialization, quantum sensors are already being used in the real world, El Alami said, but technology readiness varies depending on the use cases. “Some of the technologies are already commercialized and are already widely used.”

Technology maturity varies across use cases

There are already millions of chip-scale tunnelling magneto resistance (TMR) sensors deployed for remote current sensing in the automotive sector, while bio-magnetic imaging with optically pumped magnetometers (OPMs) show potential but are at a much earlier development stage. El Alami said the spectrum of quantum sensors range from those in early speculative research stage to full-scale commercialization.

While sensitivity is key differentiator for quantum sensors, what makes it quantum isn’t as clear cut as it is for computers, El Alami said, but the principle is that a system is quantized to the point where it can measure things on an extremely sensitive, incredibly low scale. A quantum sensor system could use atoms controlled by lasers and suspended in a gas, a superconducting system, or nitrogen vacancy sensors in diamond, he said.

The biggest advantage to using a quantum sensor rather than classical counterparts is its high sensitivity. “We're not just talking something twice as sensitive. It's usually orders of magnitude more sensitive to hundreds or thousands of times more sensitive,” El Alami said.

Typically, the goal is to use the cheapest components available to keep overall system costs down, which is challenging with quantum sensors, and it’s why they are being used where extremely sensitive magnetic sensors are required, such as monitoring electrical signals from the heart or from the brain, El Alami said. “The electrical signals in the brain and in the hearts are just so faint that you can't measure with something that isn't as sensitive as a quantum sensor,” he said. “You're looking at a premium product for high-end applications.”

That means you’re not likely to see quantum sensors show up in consumer electronics, he said. And depending on how they are made, a quantum sensor can be sensitive to noise and interference. Those based on an artificial diamond that is implanted with mirin atoms could be suitable for automotive or for manufacturing applications, and even more robust than a classical sensor that uses a semiconductor.

Quantum sensors offer GPS alternative

Today, El Alami said the two main areas where quantum sensors are pushing forward are in medical and navigation. For the latter, the appeal is due to an increase in GPS attacks, which means planes or ships can't properly navigate.

For quantum sensor navigation, software is just as important as the hardware, Michael Biercuk, CEO of Q-CTRL told Fierce Electronics in an interview. He said the biggest impediment to commercialization of quantum sensing technology is what works in the lab often doesn’t work in real-world conditions. “Our focus has been on addressing that problem with a combination of hardware and software that overcomes the challenges.”

Q-CTRL makes magnetometers that are augmented with software to enable navigation in the absence of GPS, Biercuk said. “Enabling new forms of GPS navigation consumes most of our effort.”

He said traditionally the focus for quantum sensing development has been on hardware by making it smaller and better. “We came in software-first and then began making decisions about how the hardware could be changed, how it could be simplified, and how it could be augmented by co-designing the hardware and software.”

For customers in government, defense, commercial aviation, and shipping who see GPS attacks as their primary strategic threat, the cost of quantum sensing technology is worth the price given the safety risks they are looking to mitigate, Biercuk said. “They will spare no expense to fix the challenge that they've encountered.”

And although Q-CTRL is offering high-end solutions, he said they do span a wide range of price points.

Magnetic navigation using quantum sensors operates on a similar principle as drones do by identifying landmarks. “We're now identifying magnetic landmarks, but in order to make this work, you have to pull out very, very small magnetic signatures,” Biercuk said.

In a metal airplane, a quantum magnetometer can be overwhelmed by interference, which Q-CTRL addresses through software.

object with plane in flight diagram

While quantum sensors are more expensive, they’re not always a luxury item, Biercuk said, and they offer the benefits in terms of sensitivity and stability. “The unsung hero of quantum sensors is that the output does not change significantly with time.” That means they don’t suffer from “drift,” he said. “Drift is the killer in almost all high-end applications.”

Quantum sensing is also passive, Biercuk said, which makes it more secure. “It doesn't send out a signal like Doppler radar or LIDAR might. In a commercial shipping situation, you might not care, but if it's a defense aviation platform, you don't want to be giving away your location.”

Heart disease detection could take a quantum leap

SandboxAQ, an Alphabet spinoff, is also developing quantum sensors for navigation as well as medical applications. Stefan Leichenauer, VP of engineering, said quantum technology isn’t exactly new – an MRI is technically quantum sensing technology. What companies are exploring today are the next frontier, he said in an interview with Fierce Electronics.

In 2019, Sandbox set out to tackle the world’s No. 1 killer, cardiovascular disease, by leveraging quantum sensors for magnetocardiography, which measures magnetic fields of the heart. Leichenauer said the advantage is that these fields propagate throughout the human body without any kind of obstruction.

The challenge, however, is that quantum sensors are expensive and are not yet at the stage of development where they can be miniaturized and be put in the hospital workflow without any obstruction, Leichenauer said. “Their cost is very either prohibitively expensive or their footprint is just large. This is what we're trying to tackle.”

He added that the tricky part of sensors is that if they work, they pick things you want and don’t want. “In the presence of overwhelming noise, you're looking at a needle in a haystack.”

And in a real world environment, such as healthcare, usability is essential, Leichenauer said. “It needs to be friendly to the clinician that uses it.” Healthcare is also heavily regulated, he added. “You need to run a lot of clinical studies.”

Advancements in one application area can benefit other areas, noted CTRL-Q’s Biercuk. “There's a huge amount of knowledge transfer between technologies.” The software the company built could be used in biomedical applications, he said.

Despite all the attention and investment directed at quantum sensors, Biercuk said that CTRL-Q’s demonstration that quantum assure navigation system could outperform the best GPS alternative is the first major milestone for the technology since the development of atomic clocks 40 years ago.

“Quantum sensing has been an area of a huge amount of exploration,” he said. “It's got a huge amount of potential and there has been a large amount of investment made mostly at the research levels.”

By: DocMemory
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