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[8], which can be exploited both for fundamental and practical measurements. Here, we demonstrate [10] for the first time extremely smooth, coherence-preserving matterwave guides based on time-averaged adiabatic potentials (TAAP) [9]. 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.

[1] Gustavson, T. L., Bouyer, P. & Kasevich, M. A. Precision rotation measurements with an atom interferometer gyroscope. Phys. Rev. Lett. 78, 2046–2049 (1997).
[2] Rosi, G., Sorrentino, F., Cacciapuoti,L.,Prevedelli,M.&Tino,G.M. Precision measurement of the Newtonian gravitational constant using cold atoms. Nature 510, – (2014).
[3] Dutta, I. et al. Continuous cold-atom inertial sensor with 1 nrad/sec rotation stability. Phys. Rev. Lett. 116 (2016).
[4] Kovachy, T. et al. Quantum superposition at the half-metre scale. Nature 528, 530–533 (2015).
[5] van Zoest, T. et al. Bose-Einstein condensation in microgravity. Science 328, 1540–1543 (2010).
[6] Barrett, B. et al. Dual matter-wave inertial sensors in weightlessness. Nat. Commun. 7, 13786 (2016).
[7] Soriano, M. et al. Cold atom laboratory mission system design. 2014 IEEE Aerosp. Conf. (2014).
[8] Amico, L., Birkl, G., Boshier, M. & Kwek, L.-C. Focus on atomtronics-enabled quantum technologies. New J. Phys. 19, 20201 (2017).
[9] Lesanovsky, I. & von Klitzing, W. Time-Averaged Adiabatic Potentials: Versatile Matter-Wave Guides and Atom Traps. Phys. Rev. Lett. 99, 83001 (2007)
[10] Pandey et al. Accepted for publication in Nature
Go to day