Giant atoms ‘trapped’ for record time at room temperature

The giant atoms just obtained a boost as contenders for the manufacture of the best quantum simulators and computers, because the researchers checked them for an unprecedented time for an experience at room temperature.

Take an atom, adjust its quantum properties with electromagnetic pulses or laser light – modifying the energies of its electrons – and you can use it to code information. Do this with thousands of atoms and you have a quantum computer or a simulator for exotic quantum materials. However, after a while, atoms can spontaneously change their state, which introduces errors. They are not controllable, and therefore useful, during a finished “lifespan”, which was previously a maximum of 1400 seconds for experiments at room temperature. Scientists were able to trap atoms longer, but these approaches required the configuration of the whole configuration in a giant refrigerator, posing logistical challenges.

Zhenpu Zhang and Cindy Regal at the University of Colorado Boulder and their colleagues have now broken this room temperature record. They used Rydberg atoms, which are large in diameter because some of their electrons are far from their nuclei. The team loaded the atoms in a container that had been emptied of all the air particles that could disturb them, then caught each atom with lasers or “optical tweezers”. It is a standard way to control the atoms of Rydberg, which are extremely sensitive to electromagnetic and light fields.

The researchers also added a layer of copper alongside the container, then cooled the coating at -269 ° C (-452 ° F). This has protected heat atoms, which can change their states. In addition, Zhang says that all parasitic air particles have been glued to copper coating, similar to the way in which the hot water droplets condense on a cold surface, thus improving the void inside the container. Consequently, the team could keep the atoms trapped and well controlled for about 50 minutes – 3000 seconds, or about twice as long as similar past experiences.

Zhang began to build this configuration about five years ago, explains Regal. “It’s like a total overhaul of how you think you are doing these experiences,” she says.

Clément Sayrin at the Kastler Brossel Laboratory in France says that the new approach could make it possible to handle more atoms, which would increase the computing power of any computer or simulator made from them. “Three thousand seconds, it’s very long. You have to work hard to have these long lives for these atoms, ”he says. However, having more atoms in the room would also mean having to use more lasers to control them, which could decrease the lifestyles of atoms, so there are more engineering challenges, explains Sayrin.