白小姐论坛

Professor Sougato Bose (白小姐论坛 Physics & Astronomy and 白小姐论坛Q) discussed their team鈥檚 recent work in , where he detailed how tiny diamond crystals could be used as an incredibly sensitive and small gravitational detector capable of measuring gravitational waves (GW):

If NanoGrav uses, in effect, a GW detector light years in size, physicist Sougato Bose of 白小姐论坛 believes we could make one small enough to fit inside a cupboard. His idea relies on one of the oddest effects in quantum theory, which generally describes very tiny objects like atoms. Quantum objects can be placed in so-called superpositions, meaning that their properties aren鈥檛 uniquely defined until they鈥檙e measured: more than one outcome is possible.

Quantum scientists can routinely put atoms in a quantum superposition 鈥� but such peculiar behaviour disappears for big objects such as footballs, which are either here or there whether we look or not. As far as we know, it鈥檚 not that a superposition is impossible for something that big 鈥� it鈥檚 just impossible to sustain for long enough to detect it, because the superposition is too easily destroyed by any interaction with the object鈥檚 surroundings.

Bose and his colleagues suggest聽that if we can create a quantum superposition of an object intermediate in size between an atom and a football 鈥� a tiny crystal about a hundred nanometres across, around the size of a large virus particle 鈥� the superposition will be so precarious that it would be sensitive to a passing GW. In effect the two possible states of a quantum superposition can be made to interfere like two light waves 鈥� and distortions of spacetime caused by a GW would show up as a change in that interference.

Bose thinks that diamond nanocrystals held within a vacuum much more empty than outer space and cooled to within a whisker of absolute zero could be kept in superpositions for long enough to do the trick. It wouldn鈥檛 be easy, but he says that all the technical challenges have already been demonstrated individually 鈥� it鈥檚 a matter of putting them all together. 鈥淚 don鈥檛 see any barrier in doing it over the next 10 years or so, if enough funding was there,鈥� he says.

Links:

• Read more about this 白小姐论坛Q research 鈥楾abletop quantum experiment could detect gravitational waves鈥�

Image:

A still image from a numerical simulation of a black-hole binary merger with asymmetric masses and orbital precession. Credit: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck聽Institute for Gravitational Physics), Simulating eXtreme Spacetimes (SXS) Collaboration