Of all the emerging technologies that federal agencies have begun to tackle, quantum computing has captured the public’s imagination. Like artificial intelligence and biotechnology, quantum computing is a genre of powerful new computer systems that operate on the principles of quantum physics, and it offers both promise and peril to both the public and private sectors.
This attention is due in large part to the theoretical risks that not-yet-existent fault-tolerant quantum computers could pose to current data assets stored on more vulnerable classical computers. Federal agencies are responding with aggressive efforts to secure data and digital networks at the encryption level.
Amid all the fuss surrounding quantum computing, another quantum information system has been around for a long time and has received little attention: quantum sensing. Like other quantum technologies, quantum sensors blend the principles of quantum mechanics with existing sensing techniques. Their advantage is that they can track changes in the invisible world of atoms, providing accurate and reliable measurements of the world around us.
“Sensors have been around for a long time,” said Jacob Weinstein, director of quantum technologies at MITRE. Next Government/FCW“In a quantum computer, when you’re dealing with atoms, you have to deal with each atom individually. With a quantum sensor, you don’t really have to do that.”
“We’re excited about this new technology,” said Adam Black, director of the Quantum Optics Division at the U.S. Naval Research Laboratory. Next Government/FCW Quantum mechanical sensors take existing sensing technology and use atoms, the fundamental building blocks of all matter, to precisely measure spatial aspects such as time, longitude, latitude and distance.
“You don’t necessarily need quantum mechanics to make a really good sensor,” Black says, “but in the 20th century it was recognized that quantum mechanical systems, particularly atoms and other types of systems, offered the opportunity to make sensors that were more accurate than what was possible with classical technology.”
The initial need for sensing technology arose from a desire to measure the surrounding environment beyond the reach of normal human senses. Weinstein said that incorporating atoms into sensing technology was a perfect solution, given atoms’ natural sensitivity to changes in environmental energy levels. Simply put, quantum sensors use atoms’ natural tendency to change their behavior based on slight differences in their environment to measure things with a sensitivity that other systems cannot detect.
Elliot Mason, a patent agent at Young Basil, told Nextgov/FCW that this has led to applications that are now being used for underground navigation, tracking and identifying targets with radar, and onshore drilling operations, among other things.
“Atoms can be affected by a variety of forces,” Weinstein said.
One of the best-known examples of quantum-enhanced sensors is the atomic clock. Instead of relying on traditional clock structures that are at risk of producing different time outputs due to inconsistencies in manufacturing and programming, atomic clocks measure the frequency levels between electrons pulsating like waves around atoms. By reading the fluctuations in these particles, the clock can objectively interpret changes in its surroundings.
Black added that the uniformity of atomic structure — a fundamental law that governs reality — acts as a reference point for the clock, preventing any degradation in the accuracy of the frequency reading. By detecting minute changes in the energy levels inside atoms, atomic clocks tell time more accurately than quartz or mechanical watches, he explained.
The core is that atomic clocks use their power to benchmark time against measurements of frequencies in the natural environment to read changes in the environment that result from shifts in invisible quantum energy.
“We no longer have to worry about how accurately we combine the fundamental frequency standards using both hands. [to measure time]”Now we can let nature do the really hard part for us,” he said.
This operation itself relies on other supporting technologies – depending on the particular sensor system, this might include vacuum chambers, lasers, microwave sources, etc. – but fundamentally, sensors are able to make measurements based on “unchanging natural phenomena.”
“That’s what quantum mechanics gives us,” Black said.
GPS is another area that will benefit from the application of quantum physics principles, and Black explained the work underway within the NRL to support the Navy in situations where connectivity is not available.
“We want to reduce navigation error beyond what we can achieve without GPS,” Black says, “and quantum technology is one way to achieve that.”
In response, NRL has developed an architecture that uses a continuous beam of laser-cooled atoms to measure the acceleration and rotation of a given vessel. Even at extremely low temperatures — about 10 millionths of a microkelvin below absolute zero — Black and other researchers can manipulate atoms through a vacuum cell using a process called atom interferometry.
“This technology exploits the fact that in quantum mechanics, atoms are both particles and waves, and when atoms interact with each other they create wave motion. [a] “We can measure a specific interference pattern,” Black says, “and from that interference pattern we can measure very precisely how the sensor in which the atoms are located is accelerating and rotating.”
This measurement allows the operator to know exactly where they are in relation to their surroundings.
So far, the lab demonstration has been “very successful,” Black said, and the researchers are now aiming to prove its effectiveness in a shipboard demonstration within the next two years.
In future, these systems may also prove useful below the surface.
“Extending mission duration without the need for GPS is certainly a key goal of quantum inertial sensing technology for submarines,” Black said.
Speaking at MITRE, Weinstein said: Next Government/FCW Current sensing research is working to harness the unique electronic structure of Rydberg atoms in their highly energized state to create electric field sensors, another new system that could form more efficient antennas and more resilient communications infrastructure.
“It turns out that they’re very useful for sensing electric fields, like an antenna, but not very good for transmitting electrical signals,” Weinstein said.
With such lucrative use cases, the natural next step for quantum-enabled sensor technology is commercialization. Black explained that quantum magnetometers are one such commercially available product, and miniature atomic clocks have also been on the market since the late 1950s through collaboration between the private and public sectors. Atomic gravimeters, which measure the strength of specific gravitational fields and are useful for subsurface exploration, are still available today, although commercially available to a limited extent.
However, Black noted that quantum information technology is still in its relative infancy, and he highlighted other emerging systems: integrated photonics and the properties of quantum entanglement as two avenues that could further improve these sensing technologies.
“It takes a lot of engineering to take these things from the lab to a field-ready prototype to a commercial product,” he said. “So a lot of fundamental science has been developed, [was] As it is demonstrated in the laboratory and the various supporting components become more technologically mature,
On the public research and funding front, the potential trajectory of quantum sensing systems has government agencies taking notice: In 2023, the National Science Foundation announced a new investment of $29 million in quantum sensing research. More recently, in April, two Republican senators from both houses proposed legislation to organize a more robust quantum information research infrastructure within the Department of Defense in hopes of spurring innovation in the field.
Much of the federal government’s research capacity remains dependent on the renewal of the National Quantum Initiative Act, a 2018 law that prioritizes funding for quantum information science research and development within the federal government. The act formally authorized $1.275 billion in funding over five years.
The reauthorization still awaits approval by House lawmakers, but industry advocacy groups such as the U.S. Chamber of Commerce have voiced support for passing the bill, citing national security concerns.
“The nation that leads quantum development and commercialization will gain a global strategic advantage. Other nations, notably China, are investing heavily in this sector, challenging U.S. leadership in this field,” the group of advocacy groups said in a statement Monday. “We strongly support the National Quantum Initiative Reauthorization Act and respectfully urge its enactment this year.”
