Eighty-six years since electron crystals were first proposed, physicists have now constructed them, trapping electrons in a repeating pattern. The achievement is reported in the journal Nature.

A crystal is made of a repeating pattern of particles but electrons are difficult to keep in place. So an electron crystal is like trying to organize a large number of electrons that won’t stay still — it’s the herding cats of particle physics.

However, this team had an ingenious solution. They built a Wigner crystal using layers of semi-conductors just one atom thick. They then used two different tungsten materials and created a hexagonal pattern known as a moiré superlattice by placing one material on top of the other.

Antiferromagnetism is a type of magnetism in which parallel but opposing spins occur spontaneously within a material. Antiferromagnets, materials that exhibit antiferromagnetism, have advantageous characteristics that make them particularly promising for fabricating spintronic devices.

In contrast with conventional electronic devices, which use the electrical charge of electrons to encode information, spintronics process information leveraging the intrinsic angular momentum of electrons, a property known as “spin.” Due to their ultrafast nature, their insensitivity to external magnetic fields and their lack of magnetic stray fields, antiferromagnets could be particularly desirable for the development of spintronic devices.

Despite their advantages and their ability to store information, most simple antiferromagnets have weak readout magnetoresistivity signals. Moreover, so far physicists have been unable to change the magnetic order of antiferromagnets using optical techniques, which could ultimately allow device engineers to exploit these materials’ ultrafast nature.

Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, or CNMS, contributed to a groundbreaking experiment published in Science that tracks the real-time transport of individual molecules.

A team led by the University of Graz, Austria, used unique four-probe scanning tunneling microscopy, or STM, to move a single molecule between two independent probes and observe it disappear from one point and instantaneously reappear at the other.

The STM, made available via the CNMS user program, operates under an applied voltage, scanning material surfaces with a sharp probe that can move atoms and molecules by nudging them a few nanometers at a time. This instrument made it possible to send and receive dibromoterfluorene molecules 150 nanometers across a silver surface with unprecedented control.