Giant Atoms Kept “Confined” for Record Durations at Room Temperature

Recently, giant atoms have emerged as prime candidates for the development of advanced quantum simulators and computers, thanks to researchers demonstrating control over them for an extended period in room temperature environments.

Using electromagnetic pulses or laser light, scientists can modify the quantum properties of an atom—allowing for the adjustment of electron energy to encode information. Manipulating thousands of such atoms paves the way for constructing a quantum computer or simulating unusual quantum materials. However, spontaneous state changes in atoms can cause errors, with these atoms being controllable only within a limited “lifetime,” previously recorded at up to 1400 seconds. Despite advancements in trapping atoms longer, these methods typically required refrigeration systems, leading to logistical hurdles.

Zhenpu Zhang and Cindy Regal, along with their colleagues at the University of Colorado Boulder, have shattered previous room temperature records by employing Rydberg atoms. These atoms have outer electrons positioned far from the nucleus, resulting in a larger atomic diameter. The research team successfully loaded these atoms into a vacuum chamber, effectively blocking interfering air particles and employing laser-based “optical tweezers” for precise atom manipulation. This technique is standard for controlling Rydberg atoms, noted for their sensitivity to electromagnetic fields and light.

The team enhanced their setup by adding a copper layer inside the container, which they cooled to -269°C (-452°F). This cooling shields the atoms from thermal interference that could alter their states. Additionally, Zhang explains that air particles condense onto the copper walls, akin to how water droplets form on cold surfaces, further improving the vacuum within the chamber. Consequently, they managed to maintain control of approximately 3000 seconds (or 50 minutes), which is nearly double that achieved in previous experiments.

Zhang has been developing this innovative setup for five years from the ground up. Regal adds, “This represents a significant evolution in how we approach these experiments.”

Clement Sayrin of the Kastler Brossel Laboratory in France emphasized that this new methodology may facilitate manipulating even more atoms. “3000 seconds is quite impressive. Achieving such extended lifetimes for these atoms demands considerable effort,” he states. However, as the number of atoms in the chamber increases, so does the requirement for additional lasers to control them, potentially shortening the atomic lifespans and introducing further engineering challenges, according to Sayrin.