China unveils drone-mounted quantum device for submarine detection in South China Sea

Chinese scientists’ breakthrough in magnetic detection technology could give China the edge in submarine warfare amid Sino-US tension

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Chinese scientists have revealed a breakthrough in magnetic detection technology that could eliminate ‘blind zones’ in the South China Sea, giving the China the edge in submarine warfare. Photo: Handout

Published: 6:00am, 24 Apr 2025Updated: 8:51pm, 24 Apr 2025

As US-China tensions simmer over submarine operations in the South China Sea, Chinese space scientists have unveiled a breakthrough in magnetic detection technology that could tip the balance in underwater warfare.

A drone-mounted quantum sensor system, tested successfully in offshore trials, achieved picotesla precision to track magnetic anomaly and map seabed resources while overcoming some severe practical limitations of existing devices, researchers disclosed in a peer-reviewed paper.

With such sensitivity, People’s Liberation Army’s (PLA) anti-submarine forces cannot only pinpoint a submarine but also catch the tail waves it generates, according to some previous studies.

Traditional optically pumped magnetometers (OPMs) – widely used in submarine detection – face critical “blind zones” in low-latitude regions like the South China Sea, where Earth’s magnetic field runs nearly parallel to the surface.

A nuclear-powered Type 094A Jin-class ballistic missile submarine of the Chinese People’s Liberation Army (PLA) Navy is seen during a military display in the South China Sea. Photo: CHINA OUT

When the sensor’s optical axis aligns too closely with magnetic field lines, signals weaken dramatically.