  Frictionless atom cooling in harmonic traps is formulated as a time-optimal
control problem and a synthesis of optimal controlled trajectories is obtained.
This work has already been used to determine the minimum time for transition
between two thermal states and to show the emergence of the third law of
classical thermodynamics from quantum thermodynamics. It can also find
application in the fast adiabatic-like expansion of Bose-Einstein condensates,
with possible applications in atom interferometry. This paper is based on our
recently published article in SIAM J. Control Optim.
