(麻豆淫院Org.com) -- A team led by Oxford University scientists has turned one of the key problems with quantum entangled systems - that they are easily 鈥榙isturbed鈥� by their environment - into an advantage which promises quantum sensors that are fundamentally more sensitive than their conventional counterparts.

Scientists attempting to build quantum computers have long been frustrated by the way that quantum entangled systems suffer from 鈥榠nterference鈥� from their surroundings. But now the Oxford-led team report online in this week鈥檚 Science that they have found a way to harness this sensitivity to create a system that responds to extremely weak magnetic fields - technology with potential applications in areas such as geological surveying.

The team built their system to exploit what is known as a 鈥楽hr枚dinger cat state鈥� named after the famous thought experiment by physicist Erwin Shr枚dinger: To show how the quantum world could affect our world Shr枚dinger imagined placing a cat in a sealed box with a lethal mechanism controlled by a random quantum event determining whether the cat was alive or dead. Quantum theory makes the remarkable prediction that until the box is opened the cat is both alive and dead. In the case of the Oxford work instead of all the molecules of a real cat being either alive or dead the 鈥榪uantum cat鈥� is based on the nuclear spins of a molecule, trimethlyphosphite (TMP), being either 鈥榰p鈥� or 鈥榙own鈥�.

鈥楾o create our 鈥榪uantum cat鈥� we took a star-shaped molecule with one central atom and nine atoms surrounding and applied radio frequency pulses to put it into an entangled state where all ten spins are spinning one way (鈥榓live鈥�) and the other way (鈥榙ead鈥�) at the same time,鈥� said Dr John Morton of Oxford University鈥檚 Department of Materials, an author of the paper. 鈥榃e found that compared to a non-entangled system our cat was many times more sensitive to the presence of a very weak magnetic field.鈥�

Other proposed quantum-enhanced sensor systems use photons instead of nuclear spins to sense other physical quantities such as distance.

鈥榃e are looking to turn experimental quantum systems into real world technology that people can use,鈥� said Professor Jonathan Jones of Oxford University鈥檚 Department of 麻豆淫院ics, an author of the paper. 鈥楾he next step is to investigate how a quantum sensor based on this work might be combined with existing sensors based on magnetic resonance.鈥�

Such sensors are towed across the ocean floor looking for tiny, previously undetectable, telltale fluctuations in the Earth鈥檚 magnetic field which might suggest untapped reserves of gas or oil.

鈥楳any researchers try to make quantum states that are robust against their environment,鈥� said team member Dr Simon Benjamin of Oxford University鈥檚 Department of Materials, 鈥榖ut we went the other way and deliberately created the most fragile states possible.鈥�

Provided by Oxford University ( : )