Tobias Jenke

Ramsey's method of separated oscillating fields and its application to gravitationally induced quantum phase shifts

We propose to apply Ramseys method of separated oscillating fields to the spectroscopy of the quantum states in the gravity potential above a horizontal mirror. This method allows a precise measurement of quantum mechanical phaseshifts of a Schroedinger wave packet bouncing off a hard surface in the gravitational field of the Earth. Measurements with ultracold neutrons will offer a sensitivity to Newtons law or hypothetical short-ranged interactions, which is about 21 orders of magnitude below the energy scale of electromagnetism.

Neutron interferometry constrains dark energy chameleon fields

Abstract We present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant β is less than 1.9 × 10 7 for n = 1 at 95% confidence level, where n is an input parameter of the self-interaction of the chameleon field φ inversely proportional to φ n .

Probing neutron's electric neutrality with Ramsey Spectroscopy of gravitational quantum states of ultra-cold neutrons

We propose to test the electric neutrality of neutrons by a new technique using the spectroscopy of quantum states of ultra-cold neutrons in the gravity potential above a vertical mirror. The new technique is an application of Ramsey’s method of separated oscillating fields to neutron’s quantum states in the gravity potential of the earth. In the presence of an electric field Ez parallel or antiparallel to the direction of the acceleration of the earth g, the energy of the quantum states changes due to an additional electrostatic potential if a neutron carries a non-vanishing charge. In the long run our new method has the potential to improve the current limit of 10 21 qe for the electric charge of the neutron by 2 orders of magnitude. PACS numbers:

Influence of the chameleon field potential on transition frequencies of gravitationally bound quantum states of ultracold neutrons

We calculate the chameleon field potential for ultracold neutrons, bouncing on top of one or between two neutron mirrors in the gravitational field of the Earth. For the resulting non--linear equations of motion we give approximate analytical solutions and compare them with exact numerical ones for which we propose the analytical fit. The obtained solutions may be used for the quantitative analysis of contributions of a chameleon field to the transition frequencies of quantum states of ultra-cold neutrons bound in the gravitational field of the Earth.

Vectorial velocity filter for ultracold neutrons based on a surface-disordered mirror system.

We perform classical three-dimensional Monte Carlo simulations of ultracold neutrons scattering through an absorbing-reflecting mirror system in the Earths gravitational field. We show that the underlying mixed phase space of regular skipping motion and random motion due to disorder scattering can be exploited to realize a vectorial velocity filter for ultracold neutrons. The absorbing-reflecting mirror system proposed allows beams of ultracold neutrons with low angular divergence to be formed. The range of velocity components can be controlled by adjusting the geometric parameters of the system. First experimental tests of its performance are presented. One potential future application is the investigation of transport and scattering dynamics in confined systems downstream of the filter.

Exact solution for chameleon field, self-coupled through the Ratra-Peebles potential with n = 1 and confined between two parallel plates

We calculate the chameleon field profile, confined between two parallel plates, filled with air at pressure

Acoustic Rabi oscillations between gravitational quantum states and impact on symmetron dark energy

P={10}^{\ensuremath{-}4}\text{ }\text{ }\mathrm{mbar}

Realization of a gravity-resonance-spectroscopy technique

and room temperature and separated by the distance

Gravity Resonance Spectroscopy Constrains Dark Energy and Dark Matter Scenarios

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Q-BOUNCE—Experiments with quantum bouncing ultracold neutrons

, in the chameleon field theory with Ratra\char21{}Peebles self-interaction potential with index