A unified theory of tunneling times promoted by Ramsey clocks

Abstract

What time does a clock tell after quantum tunneling? Predictions and indirect measurements range from superluminal or instantaneous tunneling to finite durations, depending on the specific experiment and the precise definition of the elapsed time. Proposals and implementations utilize the atomic motion to define this delay, even though the inherent quantum nature of atoms implies a delocalization and is in sharp contrast to classical trajectories. Here, we rely on an operational approach: we prepare atoms in a coherent superposition of internal states and study the time read off via a Ramsey sequence after the tunneling process without the notion of classical trajectories or velocities. Our operational framework (a) unifies definitions of tunneling delay within one approach; (b) connects the time to a frequency standard given by a conventional atomic clock which can be boosted by differential light shifts; and (c) highlights that there exists no superluminal or instantaneous tunneling.

9 pages, 5 figures

References in corpus (9)

• Atom Interferometers
• Systematic evaluation of an atomic clock at 2e-18 total uncertainty
• An ${}^{27}$Al${}^{+}$ quantum-logic clock with systematic uncertainty below $10^{-18}$
• Interferometry with Bose-Einstein Condensates in Microgravity
• Matter wave lensing to picokelvin temperatures
• Optical Lattice Induced Light Shifts in an Yb Atomic Clock
• Accuracy of transfer matrix approaches for solving the effective mass Schrödinger equation
• Clock spectroscopy of interacting bosons in deep optical lattices
• Transfer matrix for long-range potentials