Measurement of gravitation-induced quantum interference for neutrons in a spin-echo spectrometer

Abstract

With a neutron spin-echo reflectometer (OffSpec at ISIS, UK) it is possible to measure the gravitation-induced quantum phase difference between the two spin states of the neutron wave function in a magnetic field. In the small-angle approximation, this phase depends linearly on the inclination angle of the neutron beam with respect to the horizontal. This also holds for the Bonse-Hart interferometer used in the Colella-Overhauser-Werner experiments and should be taken into account. Neglecting this term could yield deviations up to 1% per degree inclination angle. The gravitation-induced quantum phase as measured with OffSpec with an accuracy of 0.1% agrees with the theoretically expected results.

Atom Interferometer Gyroscope with Spin-Dependent Phase Shifts Induced by Light near a Tune-Out Wavelength

“…This work is a new application for tune-out wavelengths, paves the way for improving precision measurements of tune-out wavelengths, and demonstrates a new technique for atom interferometer gyroscopes. The spin-multiplexing techniques demonstrated here may find uses in other atom [12,13] and neutron [45,46] interferometry experiments, and also in NMR gyroscopes and NMR spectroscopy. This work is supported by NSF Grant No.…”

Search for exotic spin-dependent couplings of the neutron with matter using spin-echo based neutron interferometry

“…The spin-independent phase shift of the neutron from Newtonian gravity was observed in the famous Colella, Overhauser and Werner (COW) experiment using a perfect crystal interferometer [51]. The precision of the COW measurement on the neutron was improved by almost 1 order of magnitude using a neutron spin echo interferometer [52]. In that work it was shown that the gravitationally induced quantum phase shift of the neutron agreed to within 0.1% of the value expected from theory.…”

“…Offspec is a time of flight instrument equipped with a series of four parallelogram shaped static magnetic fields each with an rf flipper at the center. The instrument has been described in a number of publications [58][59][60] and in our previous gravity experiment [52]. A schematic overview is presented in Fig.…”

“…Both Drabkin flippers have a length of 400 mm, windings at a radius of 85 mm, and a magnetic-metal shield with radius 90 mm. Similar to the procedure described in [52,59] the spinecho-length constant was determined in both the vertical and horizontal modes. The result for the horizontal mode is shown in Fig.…”

Fundamental Features of Quantum Dynamics Studied in Matter-Wave Interferometry—Spin Weak Values and the Quantum Cheshire-Cat

“…A completely different approach is offered by the concept of neutron polarimetry [19]. This makes gravitational phase measurements with the spin-echo spectrometer possible, where much longer path lengths and a white beam with a high intensity are available [20].…”