September 16, 2026 -- Rydberg atoms are considered promising building blocks for quantum computers and their precursors, quantum simulators. Researchers at the 5th Institute of Physics of the University of Stuttgart have achieved record values for the lifetime, size, and storage time of circular Rydberg atoms, a special form of Rydberg atom in which electrons move in a stable circular orbit around the nucleus. The findings were published in Nature Communications.

Quantum simulators replicate quantum systems for research purposes and are the precursors to future quantum computers. “One major challenge in developing high-performance quantum simulators was that Rydberg atoms are highly sensitive and remain stable for only a short time. We overcame this challenge and increased the stability of the atoms by a factor of 20,” says Prof. Dr. Tilman Pfau, head of the 5th Institute of Physics. Rydberg atoms are important building blocks for neutral-atom quantum technologies, which use neutral (i.e., uncharged) atoms that can be trapped and controlled with laser light. They are several thousand times larger than normal atoms and can therefore interact with one another over unusually long distances of about 5 µm. Although this is only about one-tenth the thickness of a human hair, it is a huge distance in the tiny world of atoms.

Record values achieved for lifetime, size, and storage time

“We set three international records at once: the longest lifetime ever measured for individual Rydberg atoms, the largest controlled circular Rydberg atoms, and the longest storage time for such atoms in optical tweezers,” says Dr. Florian Meinert, group leader at the 5th Institute of Physics.

To achieve this, the researchers forced the highly excited electron in the Rydberg atom into a circular orbit that remained stable for 11 ms, more than 20 times longer than comparable states in free space. The electrons move in orbits about 1.1 µm in diameter; these are roughly 10,000 times larger than those in ordinary atoms. The researchers were also able to trap the atoms for 133 ms using a laser beam, thereby setting another record. “These records open up new possibilities for making quantum simulators more powerful, performing more computations, and controlling quantum systems with greater precision,” says Einius Pultinevicius, a doctoral researcher in Meinert’s team.

Creating long-lived Rydberg atoms at room temperature

“We achieved these record results at room temperature without the costly liquid helium cooling previously required,” says Meinert. The researchers accomplished this by refining a physical concept from the 1980s: shielding the atoms from interfering thermal radiation using special metal walls. Even at normal room temperature, the environment is not completely “quiet”; every surface emits invisible microwave radiation that can destabilize sensitive Rydberg atoms. Until now, such experiments have therefore required complex cooling systems. The team placed the atoms between two transparent, electrically conductive plates that suppress the interfering microwaves. “Our results show that extremely long-lived Rydberg atoms are possible even at room temperature. We have refined a well-known concept in physics for use in modern quantum platforms,” says Meinert.

Longer-lasting stability is a prerequisite for more powerful quantum computers

“These advances could play an important role in the development of quantum simulators and quantum computers,” says Pfau. Neutral atoms in optical tweezers are among the most promising platforms for scalable quantum simulators. The high stability of Rydberg atoms makes it possible to preserve quantum information for longer and more precisely control interactions between atoms. Researchers expect this to enable quantum computers to perform calculations for longer with fewer errors. With the records it has set, the University of Stuttgart now has a globally unique experimental platform for circular Rydberg atoms. The researchers plan to use this platform to develop novel quantum computers, quantum simulators, and high-precision quantum sensors.