Is the quantum adiabatic theorem consistent?

Understand

The quantum adiabatic theorem states that if a quantum system starts in an eigenstate of the Hamiltonian, and this Hamiltonian varies sufficiently slowly, the system stays in this eigenstate.

• We investigate experimentally the conditions that must be fulfilled for this theorem to hold.
• We show that the traditional adiabatic condition as well as some conditions that were recently suggested are either not sufficient or not necessary.
• Experimental evidence is presented by a simple experiment using nuclear spins.