The Clock that Changed the World
Ye group's revolutionary quantum-gas clock uses a 3D optical lattice to hold the clock's ~10,000 ultracold 87Sr atoms—accurate to 10-23. Image credit: Steven Burrows / JILA
Imagine A Future . . .ÌýThe International Moon Station team is busy on the Moon’s surface using sensitive detectors of gravity and magnetic and electric fields looking for underground water-rich materials, iron-containing ores, and other raw materials required for building a year-round Moon station. The station’s mission: launching colonists and supplies to Mars for colonization. Meanwhile, back on Earth, Americans are under simultaneous assault by three Category 5 hurricanes, one in the Gulf of Mexico and two others threatening the Caribbean islands. Hundreds of people are stranded in the rising waters, but thanks precision cell-phone location services and robust cell-tower connections in high wind, their rescuers are able to accurately pinpoint their locations and send help immediately.
Other new technologies in this revolutionary new era of quantum devices include precision instruments searching for dark matter and dark energy, ultraprecise electronics, unbreakably secure military communications, and ordinary laboratory-sized gravitational-wave detectors and x-ray lasers. There are also advanced scientific experiments making use of the most accurate absolute measurements in history––accurate to 10-23. These technologies were unheard of in 2017, when the world’s first quantum-gas optical-lattice clock demonstrated its capabilities by measuring a 3.5 X 10-19Ìýfractional frequency shift in 2.2 hours of averaging time.
The strontium-87 (87Sr) lattice optical atomic clock was the first in history to cool its atoms to quantum degeneracy. Quantum degeneracy occurs when all the atoms in the clock occupy their lowest-possible energy level1. Lowering the temperature of the clock’s 10,000Ìý87Sr atoms to quantum degeneracy allowed Campbell’s team to capitalize on the atoms’ quantum correlations to significantly improve both the accuracy and speed of measurement.
The quantum-gas clock makes its measurements about 10 times faster (with 10 times less averaging time required) than previous clocks that use thermal atomic gases. Looking forward, as the Ye team further masters the details of quantum-gas clock technology (expected to be challenging, but doable), both the quantum-gas clock’s accuracy and measurement speed should continue to significantly improve.