An atom optics experiment to investigate faster-than-light tunneling

Abstract

We describe a series of atom optics experiments underway a t T oronto for investigating tunnelling interaction times of various sorts. We begin by discussing some outstanding issues and confusions related to the question of whether or not superluminal tunnelling can be construed as true faster-than-light \signal propagation," a question which w e answer in the negative. We then argue that atom optics is an arena ideally suited for addressing a variety of remaining questions about how, where, and for how long a particle interacts with a tunnel barrier. We present recent results on a modied \delta-kick cooling" scheme which w e h a ve used to prepare Rubidium atoms with one-dimensional de Broglie wavelengths on the order of an optical wavelength, along with simulations showing that from these temperatures, we will be able to use acousto-optically modulated dipole-force barriers to velocity-select ultracold atom samples ideal for future tunnelling experiments.

Time of arrival through interacting environments: Tunneling processes

“…One is the ordinary medium (plasma, dielectric, etc.) which consists of "matter" [1][2][3][4]. The other is the nontrivial structure of the vacuum due to field theoretical fluctuations [5] or effects of quantum gravity [6,7].…”

Probing Quantum Violations of the Equivalence Principle

“…It is only in the last decade that the CFRs have becomes experimentally accessible. Recent experiments on tunneling times indicate that the standard wisdom may not be the entire story [6][7][8][9][10][11]. Specifically, experiments such as described in Refs.…”

“…In the context of neutron interferometry, the general-relativistic gravity not only probes the total energy, as encoded in the the time-time component of the energy-momentum tensor, τ µν (x), of the test particle, but it is also sensitive to the energy currents (such as those represented by momentum flux coming from CFR and encoded in the timespace part of the τ µν (x). 7 For this reason, and because these enter phases in quantum mechanical evolution of a quantum systems, CFR may affect gravitational evolutions of a system. Since neutron (and Earth) must carry CFR contributions, the discrepancy observed in the gravitationally induced phases in in the latest neutron interferometry experiments may be probing D harmonic oscillator.…”

“…Also note that ∞ −∞ ρ 0,K (x)dx = (1/4)hω, consistent with results given in Eqs. ( 5) and (7). 7 The initial theoretical lesson learned from the neutron interferometry was that there exist quantum gravitational effects that depend on the test-particle mass.…”

Superluminal Photonic Tunneling in Inhomogeneous Waveguides

“…Some recent publications [7,23,38] have shown up the possibility of electromagnetic waves moving with superluminal velocities higher than the vacuum speed of light c 0 . The group velocity, which is the velocity of the peak of a narrowband wave packet, has been found to become superluminal [24] in the case of evanescent modes tunneling through a cutoff barrier (Fig.…”