Speaker
Description
Optical clocks based on atoms and ions probe relativistic effects with unprecedented sensitivity by resolving time dilation through frequency shifts. However, all measurements of time dilation so far are effectively classical, stemming from classical motion. Here we show that the first tests of time dilation where the proper time is no longer a single classical parameter can be achieved with atomic clocks. We apply a Hamiltonian formalism to derive time dilation effects in atomic clocks from first principles, and show how second-order Doppler shifts (SODS) due to the vacuum energy arise (vSODS). We then isolate the quantum-second-order-Doppler-shift (qSODS), a new effect for which a semiclassical description of proper time is insufficient, and which arises due to interference of relativistic effects in both time and length. We show that both vSODS and qSODS are within reach of near-future experiments with trapped ion clocks.
