December 9, 2023

Q-CTRL, which uses very small atoms to guide very large submarines, has been awarded a contract by the Australian Department of Defense to develop a quantum mechanical system for AUKUS treaty partners to navigate submarines during long-duration underwater missions.

The greatest advantage of a submarine is its stealth. Modern military submarines are extremely difficult to detect once submerged. This makes such ships not only great weapons of war, but also weapons of peace, as submarines can be sent to unstable regions as a show of force rather than outright provocation. In fact, the same effect can be achieved without even sending them at all.

However, this ability comes at a price. One of them is that submarines are harder to pilot than surface ships. Once under the waves, they are cut off from GPS signals and unable to see the sun or stars, so captains can only use gyrocompass and inertial guidance systems for dead reckoning, which automatically calculates the ship’s position by measuring how the ship is turning and accelerating. Heading and position along all three axes.

This system works on all modern submarines, but is also very limited. Over time, the guidance system accumulates errors, and the ship drifts farther and farther off course until it is miles away from where it should be. This means that subs must occasionally reach periscope depth to navigate, which also makes them easy to detect.

To overcome this problem, Q-CTRL is developing a system that uses quantum sensors to more accurately do what current inertial guidance systems do. It exploits so-called quantum sensing, which exploits special properties of quantum mechanics, including quantum entanglement, quantum interference and quantum state compression.

Simplified to a simple level, this means that a quantum navigation system can use the motion of individual atoms to precisely determine the course and position of a submarine and maintain extremely high accuracy. According to Q-CTRL, such a system can calculate the position of a submerged vessel to within one mile (1.6 kilometers) of every 1,000 hours of submerged operation.

One of the key factors is the concept of software robustness. One downside of quantum sensing is that it is very susceptible to interference, which can introduce a lot of noise into the calculations, reducing reliability. But using special software analysis, the system can be programmed to look for the signal of interest and reject interference.

As the technology was developed under the AUKUS treaty, it will not only be used by Australia, but also shared with the US and UK.

“From day one, we knew that our expertise in quantum control could unlock entirely new applications of quantum technology,” said Q-CTRL CEO and founder Professor Michael J. Biercuk. “We have shown that we can Improving the performance of quantum computers and quantum sensors by orders of magnitude – entirely through software. Now we are excited to apply these capabilities to a key Australian defense mission.”

source: Q-CTRL