Coherent multi-flavour spin dynamics in a fermionic quantum gas

Microscopic spin-interaction processes are fundamental for global static and dynamical magnetic properties of many-body systems. Quantum gases as pure and well-isolated systems offer intriguing possibilities to study basic magnetic processes including non-equilibrium dynamics. Here, we report on the realization of a well-controlled fermionic spinor gas in an optical lattice with tunable effective spin ranging from 1/2 to 9/2. We observe long-lived intrinsic spin oscillations and investigate the transition from two-body to many-body dynamics. The latter involves a complex interplay of spin and spatial degrees of freedom and implies an instability of an initially band insulating state. Using an external magnetic field we control the dimensionality of the system and tune the spin oscillations in and out of resonance. Our results open new routes to study quantum magnetism of fermionic particles beyond conventional spin 1/2 systems.