NIWC Pacific and its Partners are Building a Quantum Navy

We make sense of the first three through programming rules and various fields of classical mechanics; the fourth is something else entirely.

For one, classical physics can predict, with simple mathematics, how an object will move and where it will be at any given point in time and space. How objects interact with each other and their environments follow laws we first encounter in high school science textbooks.

What happens in minuscule realms isn’t so easily explained. At the level of atoms and their parts, measuring position and momentum simultaneously yields only probability. Knowing a particle’s exact state is a zero-sum game in which classical notions of determinism don’t apply: the more certain we are about its momentum, the less certain we are about where it will be.

We’re not exactly sure what it will be, either. That particle could be both an electron and a wave of energy, existing in multiple states at once. When we observe it, we force a “quantum choice,” and the particle collapses from its state of superposition into one of its possible forms.

Just as subatomic matter can exist two ways at once, it marks a strange intersection of order and disorder. While it’s hard to hammer down exactly what or where a particle will be, energy at the subatomic level moves only in discrete, concerted packets, or quanta, defying classical notions about continuous transfer of energy.

Then there’s quantum entanglement, what Albert Einstein called “spooky action at a distance.” It’s often described as two dice that always show the same number when rolled, together or even miles apart. When an entangled particle is measured, its partner instantaneously matches the measured particle’s state.

For Joanna Ptasinski, head of NIWC Pacific’s Cryogenic Electronics and Quantum Research branch, this strangeness is what defines quantum: it’s a complex system of matter or information where these phenomena — which can’t be explained by classical notions of how the world works — are possible.

“Quantum is quirky,” said Ptasinski, who holds a doctorate in electrical engineering. “Its essence is superposition and entanglement. We’re researching the power — the naval applications — lurking behind this weirdness.”

Heisenberg’s Uncertainty Principle, superposition, and entanglement are all part of a growing mathematical framework for subatomic phenomena called quantum mechanics, and it raises questions about the nature of reality as we know it. What can we learn from entangled particles for which space — even vast expanses of it — is no obstacle? If matter exists in many forms at once until we observe it, what role does observation play in building the world around us? And how do we harness a domain defined by potentiality?

This is what NIWC Pacific scientists explore in its labs, with its partners, and on the National Science & Technology Council’s Subcommittee on Quantum Information Science. With quantum experts from across the nation, they ask: What will harnessing quantum phenomena mean for the Navy and the warfighter?

Answers fall in a few categories: sensing, computing, communications, and materials, and the Center has projects to show for each. Answers outside of practical applications have to do with building a quantum Navy: attracting dedicated talent, giving and receiving training, and contributing to national discussions about the future of quantum technology.

All answers point to a vision of a Navy equipped with even more secure communications networks, more advanced sensors, and the faster threat detection and response that comes with them. It’s a vision of improved navigation, smarter autonomous systems, and more accurate modeling and simulation. It’s unprecedented decision advantage at quantum speed in an increasingly uncertain world.

To Ptasinski, it’s more advanced supporting technologies. “That’s what is needed in order for the field to mature,” she said. “How about a dilution fridge that isn't half the size of this office? Why not a small dilution fridge? And is that even possible?”

The dilution fridge provides the low temperatures needed to measure quantum systems with accuracy. NIWC Pacific’s dilution fridge functions in the tens of millikelvin — colder than outer space — and is one of only two across all warfare centers and the Naval Research Laboratory.

With a dilution fridge, researchers can measure and manipulate qubits, or bits of quantum information. Unlike classical bits, qubits can be in superposition of both binary values 0 and 1 at the same time. That superposition is the key to quantum computing’s exponential power.

Measuring the path of a qubit through steps in a quantum system is fundamental for quantum research; it teaches us how quantum systems work. And the more we know about how they work, the more we can use them to perform powerful computations.

Ptasinski explains this quantum walk by drawing what looks like a Pachinko machine on the back of this story draft. Drop a particle in at the top and use a traditional computer to figure out in which slot it will end up at the bottom, and you’re looking at a major computational task. With just 10 entangled photons and eight layers of potential paths, knowing the probability distributions of where each particle will end up would require more circuits than there are stars in the universe.

Enter quantum. Run the same task on a quantum computer, and a qubit’s 0-and-1 superposition means more paths can be explored simultaneously. A classical computer would have to calculate the path of a bit expressing 0 separately from the path of a bit expressing 1; a quantum computer can explore both at once, allowing for faster, more intensive calculations. “It’s like doing linear algebra with complex numbers,” Ptasinski said. “And wouldn’t it be fun to be able to do it with smaller, more powerful equipment?”

To Ptasinski, fun would be the ability to build and entangle superconducting qubits, fit many qubits on a single microchip, and discover algorithms that would mitigate errors caused by environmental interferences. “It's a very exciting field because we have a lot of puzzles that still need to be solved,” she said. “Our researchers don’t want to work on something that’s been done before. We’re looking ahead at how quantum computing can solve real-life problems for the Navy.”

Exploration of the new frontier won’t decelerate anytime soon. Co-leads Naval Research Laboratory and NIWC Pacific established the Naval Quantum Computing Program Office Dec. 2 where quantum subject matter experts across all 14 naval warfare centers will collaborate on quantum applications for the Department of Defense.

The program office will manage access to the Air Force Research Laboratory’s hub and its advanced quantum computing power on the IBM Quantum Network. First up for time in the hub is a project from NIWC Pacific.

Back in the Center's own labs, scientists and engineers are making arrangements for a new government-owned facility dedicated to quantum research. They’ll make and test their own prototypes in a lab designed to perform powerful, ultra-precise quantum experimentation.

Ptasinski continues to organize training opportunities for scientists at the Center and across the country. Soon NIWC Pacific will host a professor from the Naval Postgraduate School to teach a course on the fundamentals of quantum mechanics, which will also be open to the Defense Intelligence Agency.

High performers will get a shot at a seat in IBM’s Quantum Summer School, where distinguished quantum experts teach a small group of students from across the globe. Then NIWC Pacific students will make their way back to its quantum optics laboratory for hands-on experiments led by Ptasinski and her colleagues.

“We have many dedicated and motivated scientists and engineers expanding our quantum portfolio,” Ptasinski said when asked why NIWC Pacific is the right team for the job. “Our researchers have connections to not only industry and other government labs, but also with researchers across the world. We’re the U.S. experts in high-temperature superconductor sensors. Among the warfare centers, we’re leading quantum information science and technology.”

There’s more to learn about quantum, the puzzle with no visible pieces. Zoom in and you’ll find shapeshifting pieces which match each other even miles apart, and a precarious system that falls out of its quantum state and into a classical one at the wrong temperature. But despite all its precarity and complexity, over hours of conversations about building a quantum Navy, Ptasinski expressed no doubts about the Center’s ability to solve it.

If we are experiments away from making sense of the quantum world — quanta of training, partnerships, and groundbreaking moments away — then scientists at NIWC Pacific are making strides toward the answers.

NIWC Pacific’s mission is to conduct research, development, engineering, and support of integrated command, control, communications, computers, intelligence, surveillance and reconnaissance, cyber, and space systems across all warfighting domains, and to rapidly prototype, conduct test and evaluation, and provide acquisition, installation, and in-service engineering support.