Most quantum information technologies including quantum computers -- considered a step above supercomputers -- and quantum communication that cannot be hacked are based on the principle of quantum entanglement. However, entangled systems exist in a small microscopic world and are pretty fragile. Quantum metrology, which provides enhanced sensitivity over conventional measurements in precision metrology, has also mainly relied on quantum entanglement, so that it is hard to implement in real life applications. Recently, a Korean research team has proposed a method to achieve the quantum metrology precision without using entangled resources.
A POSTECH research team led by Professor Yoon-Ho Kim and Dr. Yosep Kim (Department of Physics) has discovered a weak-value amplification (WVA) method that reaches the Heisenberg limit without using quantum entanglement. Heisenberg-limit refers to the precision ultimately achievable in quantum metrology.
WVA-based metrology, which is one of the methods for measuring quantum effects, is an approach to obtain the most information on the quantum system with minimal impact. It can efficiently measure the system without collapsing the quantum state.
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