After briefly reviewing the use of ultracold atoms for the
implementation of quantum devices, I discuss two examples of
junctions made by strongly interacting systems weakly
coupled between them. I present in the first part of the
talk recent results on the Josephson dynamics of two
ultracold fermionic gases at the unitary limit weakly linked
by a controllable barrier . In the second part I discuss
properties of 1D Bose gases and then of junctions of
Tonks-Girardeau gases. When three Tonks-Girardeau gases are
coupled, one can exactly map their Hamiltonian by means of a
suitable Jordan-Wigner transformation into the Hamiltonian
of the multichannel Kondo model. I will also show recent
results on the experimental realization of Y-geometries with
holographic traps .
 G. Valtolina, A. Burchianti, A. Amico, E. Neri, K.
Xhani, J. A. Seman, A. Trombettoni, A. Smerzi, M. Zaccanti,
M. Inguscio, and G. Roati, "Josephson effect in fermionic
superfluids across the BEC-BCS crossover", Science 350, 1505
 F. Buccheri, G. Bruce, A. Trombettoni, D. Cassettari, H.
Babujian, V. Korepin, and P. Sodano, "Holographic optical
traps for atom-based topological Kondo devices", New J.
Phys. 18, 075012 (2016).