Scientists have demonstrated a form of transport so efficient that it effectively eliminates resistance, marking what researchers describe as the most flawless flow ever observed in a physical system, according to Popular Mechanics. The achievement does not involve electricity in wires, but something arguably more fundamental: the controlled movement of atoms themselves.
The work was led by physicist Frederik Møller at the Atominstitut of Vienna University of Technology, where researchers engineered a steady current of rubidium atoms inside an ultracold quantum gas. Despite frequent collisions between atoms, the flow moved without losing energy, momentum, or mass. In transport physics, that combination has never been observed so cleanly.
Transport describes how particles, energy, or momentum move through a medium. Most everyday systems fall into one of two categories. Diffusive transport involves constant random collisions that slow motion, as seen in heat conduction or osmosis. Ballistic transport sits at the opposite extreme, where particles move freely without collisions, typically over short distances and under tightly controlled conditions. Both mechanisms impose limits on efficiency.
The new experiment occupies an unexpected middle ground. The rubidium atoms did collide, but those collisions did not degrade the flow. Instead, momentum passed cleanly from atom to atom, more like a chain reaction than random scattering. The researchers likened the process to a Newton’s cradle, where energy transfers through a line of spheres without being lost to friction.
“If currents are dissipationless, the corresponding charge carriers propagate ballistically,” the researchers said in a study recently published in Science Advances.
To create the system, the team cooled rubidium atoms to near absolute zero using a combination of laser cooling and evaporative cooling. At those temperatures, the atoms formed a one dimensional quantum gas. A microchip placed above the gas generated magnetic fields that confined and guided the atoms, forcing them into a narrow channel where their collective behavior could be precisely measured.
Crucially, the resulting flow did not fit neatly into existing definitions of transport. It was not diffusive, because scattering did not slow it down. It was not purely ballistic either, because collisions were still present. Yet energy and mass propagated without resistance, producing what the researchers call dissipationless transport.
The findings were published in the journal Science Advances and represent a new benchmark for transport efficiency. While the system operates under extreme laboratory conditions and has no immediate technological application, it challenges long held assumptions about the inevitability of resistance in physical systems.
Beyond practical considerations, the experiment opens new avenues for studying quantum matter and collective behavior. It also raises deeper questions about whether similar resistance free transport could exist for other phenomena, such as shock waves or information flow. For now, the result stands as a rare case where nature appears to allow perfect motion, at least on the smallest and coldest of stages.
