Single atom thermal machines
While thermodynamic systems are generally treated by averaging over many body systems, we seek to scale such systems down to the ultimate limit of a single atom [1,2,3,4]. We have experimentally demonstrated a nanoscale heat engine using a single ion as working gas. A Sterling-cycle engine were implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered reservoirs.
To realize such a heat engine, a single ion is trapped in a linear Paul trap with tapered geometry (see Fig. 1). It couples to thermal reservoirs which are engineered by laser radiation and tailored electronic noise on the electrodes. These reservoirs heat and cool the radial thermal states of the ion alternately. The cycle of heating and cooling is repeated resonantly with the axial eigenfrequency of the ion, transducing a change in temperature in the radial state into a coherent movement along the trap's symmetry axis.
This experiment opened a new realm for investigating thermodynamics at the single-atom level and in the quantum regime. Throughout this project we seek to provide experimental answers to many interesting questions when thermodynamics meet the quantum world.
[1] A single-atom heat engine, Science, 352, 325-329 (2016).
[2] Nanoscale Heat Engine Beyond the Carnot Limit, Phys. Rev. Lett., 112, 030602 (2014).
[3] Single-Ion Heat Engine at Maximum Power, Phys Rev. Lett., 109, 203006 (2012).
[4] Transient non-confining potentials for speeding up a single ion heat pump, New Journal of Physics, 20, 105001 (2018).