A unique image of atoms behaving like quantum waves

In 1920, physicist Erwin Schrödinger wrote an equation that predicted how “wave particles” would behave. Now researchers can perfectly recreate these predictions in the laboratory.

This is the clearest picture ever of individual atoms behaving like a wave, as predicted by quantum mechanics. These kinds of images can help researchers study this strange and poorly understood quantum behavior.

Golf Curb Package

One important idea in quantum theory is that particles such as atoms can behave like waves. The waveform that an atom can take is known as a ‘wave packet’. You can imagine it as a series of ripples on the surface of the water, but more grouped and compressed.

Physicists can accurately predict how a wave packet will change over time. For this they used the Schrödinger equation, developed by the Austrian physicist Erwin Schrödinger. This makes analyzing wave packets a great way to test how well we can manipulate and image the atom in the quantum world, says the physicist. Tariq explains The French National Center for Scientific Research and High school teachers In Paris. He and his colleagues did this simultaneously Experiment with ultracold lithium atoms.

Cooling laser

To image the atoms, the researchers had to cool them to almost absolute zero (-273.15 degrees Celsius). To do this, they placed lithium atoms in a small vacuum chamber and bombarded them with lasers and magnetic fields. As a result, their energy decreased and they became colder.

Researchers used the same tools to observe the quantum states of atoms, and thus their wave form. They arranged the atoms so that they were not too close to each other and made sure that the quantum state of each atom corresponded to a wave packet. They then released the atoms to see how the wave packets changed.

According to the rules of quantum physics, you cannot image a wave packet. If you try to visualize a wave function, the waveform collapses and you only see a particle at a certain place. The researchers were able to overcome this problem by taking multiple images and taking an average. By doing this, they reconstructed the so-called probability density of the place where the atom is located, which corresponds to a wave packet.

In the pictures, each atom started out as a tiny dot. The Schrödinger equation predicts that a wave packet that is free to move will propagate over time. The images of lithium atoms taken by Yifshah and his colleagues showed exactly that. They were also able to show how changing the initial properties of a wave packet, such as its width, changed the way the beam propagated. In all cases, the notes on their photos matched the famous equation.

Precise control

physical Peter Schaus Wave packets are a well-understood part of quantum theory, making these findings unsurprising, say researchers from the University of Virginia in the US. But it shows that the researchers had a high degree of control over the processes by which they cooled the atoms and accurately imaged them.

This examination provides the opportunity for further research. The atoms used in the experiment belong to a type of particle called… fermions. According to Schauss, fermions are very interesting to physicists, especially if there is a mutual interaction. For example, theorists believe that extremely cold fermions, with strong mutual interactions, can form new quantum phases of matter. However, the mathematics that can predict exactly how this will happen is very difficult. Experiments can provide more clarity, Schaus says. But until now it has been difficult to cool fermions to very low temperatures.

Yavsah and his colleagues now hope to use their controlled method for such systems with strongly interacting atoms. In extreme cases, their images could reveal quantum wave behavior similar to that of quantum matter inside incredibly compact neutron stars. Or in the dense “soup” of particles that existed immediately after the Big Bang.