Some of the most sensitive and precise measurements to date are based on matterwave interferometry using freely falling atoms. Examples include ultra-high-precision measurements of inertia, gravity and rotation sensing [1-3]. Unfortunately, interaction time has to be very long in order to achieve very high sensitivities, resulting in interferometers often ten or even one hundred meters high or in the experiments having to be carried out in micro gravity on the space station[4–7]. Coherent matterwave guides and atomtronics will make possible highly compact devices having much extended interaction times and thus much increased sensitivity, which can be exploited both for fundamental and practical measurements. Here, we demonstrate  for the first time extremely smooth, coherence-preserving matterwave guides based on time-averaged adiabatic potentials (TAAP) . We do so by guiding Bose-Einstein condensates (BEC) over macroscopic distances without affecting their internal coherence: We use a novel magnetic accelerator ring to accelerate BECs to more than 16x their velocity of sound. We transport the BECs in the TAAP over truly macroscopic distances (15 cm) whilst preserving their internal coherence. The BECs can also be released into the waveguide (Fig.1c) with barriers controllable down to 200 pK giving rise to new regimes of tunnelling and transport through mesoscopic channels. The high angular momentum of more than 40000 ħ per atom and high velocities raises interesting possibilities with respect to the higher Landau levels of quantum Hall states of atoms and open new perspectives in the study of superfluidity. Coherent matterwave guides will result in much longer measurement times (here > 4 s) and much increased sensitivity in highly compact devices. This will raise the spectre of compact, portable guided-atom interferometers for fundamental experiments and applications like gravity mapping or navigation.
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 Pandey et al. Accepted for publication in Nature
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