Researchs at Swansea University found a way to use mirrors to reduce quantum noise. This noise disrupts measurements of small objects like nanoparticles, which are extremely small bits of matter. When scientists measure these particles, they use photons. However, photons push the particles they hit. This push, called backaction, causes disturbance.
In a study published in Physical Review Research, the researchers showed backaction works both ways. They used a hemispherical mirror, a curved mirror shaped like half a sphere. They placed a particle at the mirror’s center. Under specific conditions, the particle matched its mirror image. This made it impossible to measure the particle’s position using scattered light.
“Our work has shown that if you can create conditions where measurement becomes impossible, the disturbance disappears too," said researcher Rafal Gajewski in a press release.
Applications in Quantum Experiments
This discovery has exciting uses. It could create special quantum states with larger objects. It may test quantum physics on bigger scales. The discovery could explore how quantum mechanics connects to gravity. It might also build ultra-sensitive sensors to detect tiny forces. These sensors could help projects like MAQRO, a space mission to test quantum physics with large objects.
Research leader James Bateman noted the link between information and disturbance in quantum mechanics. Surprisingly, backaction vanished when light scattering was strongest. This defies common expectations. By shaping the particle’s environment, scientists control what information they get. This reduces quantum noise. It opens doors for better quantum experiments and precise measurements.
The researchers are now planning experiments to test this idea. They aim to develop new quantum sensors. This work builds on levitated optomechanics, a field where lasers hold and control tiny particles in a vacuum. Recent experiments cooled particles to their quantum ground state, the lowest energy level. This shows strong control over tiny systems. The mirror technique could push quantum research further, enabling new discoveries in physics and technology.