Scientists are now capable of imaging a single cold atom in just a fraction of a second – an important technological breakthrough when it comes to studying quantum physics at an atomic level.
Crucial to this breakthrough is the technique known as super-resolution imaging. This microscopy method can overcome the restrictions in resolution caused by the diffraction limit, and it has been used in both biological and chemical investigations.
This study firmly brings this approach to quantum mechanics as well. The findings are reported in the journal Physical Review Letters.
Making this happen is easier said than done, but researchers from the University Of Science And Technology Of China have been able to apply the technique to a single cold atom contained within an ion trap. This is the first direct super-resolved imaging of a single cold ion.
The scientists achieved a positional accuracy of 10 nanometers and a time resolution of 50 nanoseconds – an improvement of more than 10 times compared to a technique such as fluorescence imaging.
Those are fantastic numbers to be able to achieve. The team thinks that the method will be very useful to study the properties of cold atoms in ion traps such as positions, momenta, and their correlations. They also believe it might be possible to further improve it so that the spatial resolution can go below the 10-nanometer limit.
While 10 nanometers is tiny, that’s still about 22 times wider than the diameter of the Ytterbium atom imaged in this study. It is important to appreciate just how close this takes us to the atomic world, but also the hurdle to image something so small where the quantum mechanical effects become so dominant.
The other major factor that imaging requires is for particles to hit your target. That’s photons in an optical microscope, while electrons are used in an electron microscope. At our size, we wouldn’t notice the effect of bouncing photons when being observed – but when you are a tiny atom, photons can deliver a powerful kick.
The researchers believe that the technique can also be used in cold ion traps with multiple atoms in them, which is how they are often used. The approach is also compatible with other cold atom approaches such as optical lattices, neutral atom optical tweezers, and cold atom-ion hybrid systems.
This method has brought a literal new view of the atomic world.