It was deemed impossible: physicists have, for the first time, observed the wave nature of atoms (photo).

For the first time, physicists have conducted a classic quantum experiment demonstrating that particles can behave like waves using whole atoms. This was previously thought to be impossible. The new discovery, showcasing the wave nature of atoms, will aid in the creation of atomic detectors for gravitational waves that will be more sensitive than current technologies. This advancement will enable the detection of more ripples in spacetime, which still hold many mysteries. The research has been published on the arXiv preprint server, as reported by New Scientist.

In the late 1920s, physicist George Paget Thomson proved that electrons passing through a crystal diffract (meaning wave diffraction occurs — a phenomenon where waves bend around obstacles) and create a distinctive diffraction pattern. This pattern arises when a wave passes through a small opening, bending its path as it exits. The characteristic diffraction pattern was produced when passing through gaps in a crystal lattice.

Thanks to this experiment, Thomson, who later received the Nobel Prize in Physics, demonstrated that particles can also behave as waves. A few years later, physicists observed a similar diffraction pattern for whole atoms, but in that case, it involved the reflection of atoms from a surface.

Diffraction of atoms through a crystal lattice would yield much larger and more sensitive diffraction patterns, but it was believed to be impossible. The reason is that atoms with very high energy are required, but they would damage the crystal lattice. In such a case, wave diffraction could not occur. Now, physicists have for the first time diffracted helium and hydrogen atoms through a graphene sheet, which consists of a single layer of carbon atoms.

Initially, the researchers accelerated the atoms to high speeds and energies. It had previously been demonstrated that hydrogen and helium at room temperature cannot pass through graphene. Following this, the physicists directed a beam of high-energy atoms at the graphene sheet, which was expected to be damaged as a result.

However, prolonged bombardment with beams of helium and hydrogen atoms did not damage the graphene sheet. Instead, the physicists observed the characteristic circular diffraction patterns resulting from wave diffraction.

According to the physicists, the high energy of the atoms allows them to pass through the gaps in the graphene structure because they can exchange energy with the graphene atoms in an imperceptible manner. If the energy exchange could be detected, the wave nature of the atoms would be disrupted, according to the laws of quantum mechanics, and the diffraction pattern would no longer occur.

The scientists describe this process as akin to a room with many doors that are normally closed but become open at higher energies.

Physicists believe that this effect can be utilized to create an atomic interferometer that will be significantly more sensitive than existing technologies, capable of detecting gravitational waves permeating the entire universe.