F. Brito

In this work, we study quantum heat transport in a single trapped ion, driven by laser excitation and coupled to thermal reservoirs operating at different temperatures. Our focus lies in understanding how different laser coupling scenarios impact the system dynamics. As the laser intensity reaches a regime where the ion's electronic and motional degrees of freedom strongly couple, traditional approaches using phenomenological models for thermal reservoirs become inadequate. Therefore, the adoption of the dressed master equation (DME) formalism becomes crucial, enabling a deeper understanding of how distinct laser intensities influence heat transport. Analyzing the heat current within the parameter space defined by detuning and coupling strength, we observe intriguing circular patterns which are influenced by the ion's vibrational frequency and laser parameters, and reveal nuanced relationships between heat transport, residual coherence, and system characteristics. Our study also reveals phenomena such as negative differential heat conductivity and asymmetry in heat current flow, offering insights into the thermal properties of this essential quantum technology setup.

In this letter we present a protocol to engineer interactions confined to subspaces of the Fock space in trapped ions: we show how to engineer upper-, lower-bounded and sliced Jaynes-Cummings (JC) and anti-Jaynes-Cummings (AJC) Hamiltonians. The upper-bounded (lower-bounded) interaction acting upon Fock subspaces ranging from $\left\vert 0\right\rangle $ to $\left\vert M\right\rangle $ ($\left\vert N\right\rangle $ to$\ \infty$), and the sliced one confined to Fock subspace ranging from $\left\vert M\right\rangle $ to $\left\vert N\right\rangle $, whatever $M<N$. Whereas the upper-bounded JC or AJC interactions is shown to drive any initial state to a steady Fock state $\left\vert N\right\rangle $, the sliced one is shown to produce steady superpositions of Fock states confined to the sliced subspace $\left\{ \left\vert N\right\rangle \text{,}\left\vert N+1\right\rangle \right\} $.