China's Tiangong Station Cools Atoms to Record 9.7 Picokelvin 2026

China has achieved a remarkable feat in quantum physics: on its Tiangong space station, scientists cooled a cloud of about 20,000 rubidium atoms to a kinetic temperature of just 9.7 picokelvin above absolute zero. This is the coldest temperature ever recorded in a laboratory setting, according to a study published in Science. The achievement pushes the boundaries of what is possible with ultracold matter and opens new avenues for research.

Why 9.7 Picokelvin Matters

Absolute zero, at −273.15 °C, is the theoretical limit where all atomic motion ceases. Reaching temperatures just billionths of a degree above it is extraordinarily difficult on Earth because gravity causes atoms to fall and escape. In space, microgravity allows researchers to hold and study these ultracold atoms for much longer periods. The Tiangong team's 9.7 picokelvin is a new benchmark, surpassing previous records and demonstrating China's growing capabilities in space-based quantum experiments.

At such extreme cold, quantum effects that are normally masked by thermal noise become visible. Atoms begin to behave like waves, and collective quantum phenomena emerge. This is not just about setting a record; it is about creating a platform for precision tests of fundamental physics.

How They Did It: Cooling Techniques

The team used a combination of laser cooling and evaporative cooling to achieve the record. First, laser beams slowed the rubidium atoms by bombarding them with photons, reducing their kinetic energy. Then, the atoms were confined in a magnetic trap, and the most energetic ones were allowed to escape, further cooling the remaining cloud. This process created a Bose-Einstein condensate (BEC), a state of matter where many atoms occupy the same quantum state and behave as a single entity.

The microgravity environment of Tiangong was crucial. Without gravity pulling the atoms down, the trap could be made weaker, allowing the cloud to expand and cool more effectively. The team also developed advanced diagnostic tools to measure the temperature precisely.

What This Means for Science and Technology

Ultracold atoms are at the heart of next-generation technologies. They enable atomic clocks with unprecedented precision, which could improve satellite navigation and fundamental constant measurements. They are also key to quantum simulators and sensors that can detect tiny gravitational and magnetic fields.

In space, these applications become even more powerful. A BEC in microgravity can be used to create atom interferometers that are far more sensitive than their Earth-based counterparts. This could lead to better tests of general relativity, searches for dark energy, and improved Earth observation. The Tiangong experiment is a step toward a permanent cold-atom laboratory in orbit.

• Record temperature: 9.7 picokelvin above absolute zero, achieved with 20,000 rubidium atoms.
• Key technique: Laser cooling followed by evaporative cooling in microgravity.
• Quantum state: The atoms formed a Bose-Einstein condensate, exhibiting collective quantum behavior.
• Implications: Advances in quantum sensing, atomic clocks, and fundamental physics tests.
• Space advantage: Microgravity allows longer observation times and weaker traps.

Comparing Cold Atom Experiments

Several space-based cold atom experiments have been conducted, but the Tiangong result stands out for its ultralow temperature. The table below compares key missions. The background to this story is set out in China's Tiangong Space Station Set to Double in Size by 2030. A related thread runs through All of Us Atoms Audiobook Review: Extraordinary Self-Portrait. Earlier coverage in Atomic Dreams: The Wildest Nuclear Projects Ever Imagined shows how the argument developed.

The Tiangong experiment achieved a temperature roughly four orders of magnitude lower than previous space-based efforts. This leap is due to improved cooling techniques and the stable platform of the space station. A closer look at the same subject appears in Atomic-6 Space Armor: Satellite Shield Tested in Orbit. Anyone following the wider picture can start with Science: latest articles. The same theme surfaces in China Tests Space Reproduction: Can Babies Be Born in Orbit, which takes a different angle.

What to Watch Next

The team plans to further refine the experiment and extend the observation time. They also aim to create even colder samples and explore new quantum phases. As China continues to invest in its space station, we can expect more groundbreaking results in quantum science. This achievement not only highlights China's technological prowess but also underscores the importance of international collaboration in pushing the frontiers of knowledge. Context on how this played out before sits in China's Secret Shenlong Spacecraft Drops Another Unknown Object. A companion piece, China Recovers Rocket First Stage Like SpaceX and Blue Origin, approaches the same subject from another angle.