Atomic clocks could reveal role of Einstein's theory in quantum system
A new study in Physical Review Letters has used atomic clocks to study relativistic effects in interacting quantum systems.
The reconciliation of general relativity and quantum mechanics is one of the biggest challenges in science, one that continues to elude us.
Now, a new study by Anjun Chu and colleagues has examined how mass-energy equivalence (E=mc²) manifests via gravitational effects in optical lattice clocks and interacts with quantum phenomena like entanglement.
“We’ve known how gravity affects time and how quantum mechanics governs atomic behavior separately, but seeing them interact in a controllable way is revolutionary,” said Chu in a press release.
Highly precise timekeepers
To study this intersection, the researchers used optical lattice clocks, the most accurate timekeepers ever created. They trapped thousands of strontium atoms vertically in grids of laser light.
Atomic clocks rely on the steady frequency at which electrons in atoms transition between energy levels. Keeping a count of these oscillations allows atomic clocks to measure time with extremely high precision.
The effects of Einstein’s mass-energy equivalence come into play when performing high-precision measurements through two effects.
First is the gravitational redshift which causes atoms at different heights to tick at different rates, as gravity is slightly weaker for atoms higher up. Second, as atoms move, the second-order Doppler shift generates tiny changes in frequency.