Ultracold atomic clocks probe quantum effects on time
Scientists have developed highly precise ultracold atomic clocks that could detect how quantum physics influences the flow of time. By cooling atoms to near absolute zero, these devices aim to measure subtle time variations predicted by quantum theory. The research, published in Nature Communications, opens new avenues for testing fundamental physics.
Researchers at the University of Warwick, led by physicist Gavin Morley, have created ultracold atomic clocks using strontium atoms chilled to just a few millionths of a degree above absolute zero. These clocks operate by trapping the atoms in optical lattices and using lasers to track their vibrations, which serve as the ticking mechanism. The precision of these devices surpasses traditional atomic clocks, potentially allowing them to spot quantum fluctuations in time that classical physics cannot explain.
The experiment involves placing two such clocks side by side to compare their rates over extended periods. 'If quantum mechanics affects time, we should see a tiny difference between the two clocks,' Morley explained in the study. Quantum theory suggests that at microscopic scales, time might not flow uniformly due to effects like superposition and entanglement, a phenomenon untested until now.
This work builds on earlier advancements in optical lattice clocks, first demonstrated in the early 2000s. The latest iteration, detailed in a paper published on 16 October 2024 in Nature Communications, achieves stability on the order of 10^-18, meaning it would neither gain nor lose a second over the age of the universe. By isolating quantum effects from environmental noise, the clocks could reveal discrepancies predicted by theories attempting to unify quantum mechanics with general relativity.
Implications extend to quantum gravity research and improved GPS technologies, where even minuscule time errors can accumulate. However, challenges remain, including scaling the experiment to detect predicted variations as small as 10^-20 seconds. The team plans further refinements to push these boundaries, potentially reshaping our understanding of time at the quantum level.
No prior experiments have directly probed quantum time dilation in this manner, making this a pioneering effort in experimental physics.