Symmetric Bloch oscillations of matter waves

Abstract

Yb 14 MnSb 11 is a magnetic Zintl compound as well as being one of the best high temperature p-type thermoelectric materials. According to the Zintl formalism, which defines intermetallic phases where cations and anions are valence satisfied, this structure type is nominally made up of 14 Yb 2+ , 1 MnSb 9− 4 , 1 Sb 7− 3 , and 4 Sb 3− atoms. When Mn is replaced by Mg or Zn, the Zintl defined motifs become 13 Yb 2+ , 1 Yb 3+ , 1 (Mg, Zn)Sb 10− 4 , 1 Sb 7− 3 , and 4 Sb 3− . The predicted existence of Yb 3+ based on simple electron counting rules of the Zintl formalism calls the Yb valence of these compounds into question. X-ray absorption near-edge structure, magnetic susceptibility, and specific heat measurements on single crystals of the three analogs show signatures of intermediate valence Yb behavior and in particular, reveal the heavy fermion nature of Yb 14 MgSb 11 .Inthese isostructural compounds, Yb can exhibit a variety of electronic configurations from intermediate (M = Zn), mostly 2+ (M = Mn), to 3+ (M = Mg). In all cases, there is a small amount of intermediate valency at the lowest temperatures. The amount of intermediate valency is constant for M = Mn, Mg and temperature dependent for M = Zn. The evolution of the Yb valence correlated to the transport properties of these phases is highlighted. The presence of Yb in this structure type allows for fine tuning of the carrier concentration and thereby the possibility of optimized thermoelectric properties along with unique magnetic phenomena.

Twin-lattice atom interferometry

“…Moreover, diffraction phases should be greatly suppressed as in ref. 29 ; however, the inertial noise in our current setup prevents us from confirming this experimentally. Given the use of two instead of three light fields, our geometry is even more symmetric than 29 .…”

“… 29 ; however, the inertial noise in our current setup prevents us from confirming this experimentally. Given the use of two instead of three light fields, our geometry is even more symmetric than 29 . Indeed, for ideal mode overlap, our twin-lattice interferometer should be by construction not susceptible to light shifts that were reported in ref.…”

“…Here, we present twin-lattice interferometry as a method to form symmetric interferometers featuring matter waves with large relative momentum. By employing two counterpropagating optical lattices 29 , we create from a Bose–Einstein condensate (BEC) a Mach–Zehnder-type interferometer, made of wave packets with a differential momentum of >400 photon recoils, the largest reported so far. In this way, we realize a Sagnac loop with an area of A = 7.6 mm 2 on a baseline of only 2.43 mm.…”

Ultracold atom interferometry in space

“…For a systematic analysis we implemented numerical simulations of our experiments. The theoretical images of the spatial density distributions depict simulations modelling the evolution of the different spinor components of the wave packets including the atom-light interaction in position space 31 , 32 . Parameters, such as relative intensities, frequencies and the geometry, are independently determined by the experimental setup.…”

Multi-loop atomic Sagnac interferometry

“…They realised the transfer of large momenta with subsequent pulses or higher order transitions 32 – 37 and their combination with Bloch oscillations 30 , 38 , 39 . The implementation of symmetric splitting 40 – 44 was demonstrated with an effective wave number corresponding to 408 photon recoils in a twin-lattice atom interferometer 41 . A similar procedure enabled the relaunch of atoms 28 .…”