Electrons typically repel each other due to their negative charge, playing a significant role in influencing many material properties, such as electrical resistance. However, when electrons are “glued” together into pairs, they become bosons, which can coexist in the same space and execute identical motions. This phenomenon is at the heart of superconductivity, a state where materials can conduct electricity without resistance.
In a groundbreaking development, physicists from the Department of Physics at Universität Hamburg have observed a quantum state that was theoretically predicted more than 50 years ago by Japanese theoreticians. This discovery marks a significant milestone in understanding how superconductivity can be achieved in smaller, nanoscale structures.
The researchers achieved electron pairing in an artificial atom called a quantum dot, which is the smallest building block for nanostructured electronic devices. By locking the electrons into tiny cages that they built atom by atom and coupling them to an elemental superconductor, the electrons inherited the tendency towards pairing from the superconductor. This pairing of electrons is a crucial aspect of superconductivity, where electrons form bosonic pairs and can coexist in the same space, executing identical motions.