  Spin-dependent electrical injection has found useful applications in storage
devices, but fully operational spin-dependent semiconductor electronics remain
a challenging task because of weak spin-orbit couplings and/or strong spin
relaxations. These limitations are lifted considering atoms instead of
electrons or holes as spin carriers. In this emerging field of atomtronics, we
demonstrate the equivalent of a Datta-Das transistor using a degenerate Fermi
gas of strontium atoms as spin carriers in interaction with a tripod
laser-beams scheme. We explore the dependence of spin rotation, and we identify
two key control parameters which we interpret as equivalent to the gate-source
and drain-source voltages of a field effect transistor. Our finding broadens
the spectrum of atomtronics devices for implementation of operational
spin-sensitive circuits.
