Phase accumulation in Ramsey sequence missing

[gaaraneda]

There is no free evolution in the Ramsey sequence after the mesolve calculating the laser interaction. This could be introduce manually after the first mesolve for the first laser interaction.
Alternative, adding the correct initial time for mesolve, i,e, for example mesolve(H,linspace(100,300,1),state_after_first_pulse) instead of mesolve(H,linspace(0,200,1), state_after_first_pulse) if there is a waiting time of 100 us and a interaction of 200 us.

Of course, this is important only for hamiltonians time dependent in the spins.