Physicists have found that Maxwell’s fish-eye lens can entangle pairs of atoms, in the first-ever study of the lens from a quantum mechanical perspective.
What is Maxwell’s fish-eye lens?
The physicist James Maxwell devised a theoretical construct which is referred to as Maxwell’s fish-eye lens in 1854. The construct is of a lens configuration which resembles the eye of a fish. The fish-eye lens is circular and thick at the centre but thins out at the edges. Maxwell was the first to find out that a fish-eye lens would exhibit interesting optical behaviours, including that when the light shines through the lens it will travel around in perfect circles. Maxwell’s fish-eye lens is only slightly similar to commercial camera fish-eye lenses.
In a new study, physicists have studied the theoretical lens to see how individual atoms and photons could behave within it. The study is the first research into the lens from a quantum mechanical perspective. The study was carried out by physicists at MIT and Harvard University and has been published in the journal Physical Review A.
What did the study find?
In quantum mechanics, entanglement refers to when properties of one particle are linked to those of another, even over long distances. The study found that single photons can be guided through the lens due to its unique configuration, and this means that pairs of atoms become entangled. This finding is significant because no other two-dimensional device can entangle atoms over large distances. The first author of the study and student at MIT’s Department of Physics, Janos Perczel, said: “It’s this mind-blowing quantum mechanics idea of entanglement, where the photon is completely shared equally between the two atoms.”
It has previously been claimed that Maxwell’s fish-eye lens produces a perfect image, however, the study has disproved this. A perfect lens would go beyond the diffraction limit, focusing light to a point that is smaller than the light’s own wavelength and producing an image with unlimited resolution, but this is not possible with Maxwell’s fish-eye lens.
“This tells you that there are these limits in physics that are really difficult to break,” Perczel says. “Even in this system, which seemed to be a perfect candidate, this limit seems to be obeyed. Perhaps perfect imaging may still be possible with the fish-eye in some other, more complicated way, but not as originally proposed.”
How will Maxwell’s fish-eye lens influence the future of quantum mechanics?
The study suggests that fish-eye lenses could assist in entangling atoms to use them for designing quantum computers. Perczel added: “Entanglement and connecting these various quantum bits can be really the name of the game in making a push forward and trying to find applications of quantum mechanics.”