Abstract:
We study how a quantum heat engine performs across the critical value of an external parameter,
pertaining to the quantum phase transition. Considering a two-ion system subjected to a magnetic
field, we show that the system performs in a quantum Otto cycle above a critical value of the
magnetic field, while below such critical point, it does not operate in a heat cycle at all. Moreover,
at the critical point, its interaction with an ancillary ion deteriorates the performance of the system
as a heat engine. We further show that a strong interaction between the constituent ions of an
ion-based system is crucial for it to work in a heat-work cycle, while the coupling to the ancillary
system must be minimized.
