Heat rectification, heat fluxes, and spectral matching.

Heat rectifiers would facilitate energy management operations such as cooling or energy harvesting, but devices of practical interest are still missing. Understanding heat rectification at a fundamental level is key to helping us find or design such devices. The match or mismatch of the phonon band spectrum of device segments for forward or reverse temperature bias of the thermal baths at device boundaries was proposed as the mechanism behind rectification.

Fast Driving of a Particle in Two Dimensions without Final Excitation.

Controlling the motional state of a particle in a multidimensional space is key for fundamental science and quantum technologies. Applying a recently found two-dimensional invariant combined with linear invariants, we propose protocols to drive a particle in two dimensions so that the final harmonic trap is translated and rotated with respect to the initial one. These protocols realize a one-to-one mapping between initial and final eigenstates at some predetermined time and avoid any final excitations.

Tailored ion beam for precise colour centre creation.

We present an invariant-based quantum control scheme leading to a highly monochromatic ion beam from a Paul trap. Our protocol is implementable by supplying the segmented electrodes in the trap with voltages of the order of volts. This mitigates the impact of fluctuations in previous designs and leads to a low-dispersion beam of ions.

Fast ion shuttling which is robust versus oscillatory perturbations.

Shuttling protocols designed by shortcut-to-adiabaticity techniques may suffer from perturbations and imperfect implementations. We study the motional excitation of a single ion shuttled in harmonic traps with time-dependent, 'systematic' oscillatory perturbations around the nominal parameters. These elementary perturbations could form any other by superposition.

Heat rectification with a minimal model of two harmonic oscillators.

We study heat rectification in a minimalistic model composed of two unequal atoms subjected to linear forces and in contact with effective Langevin baths induced by Doppler lasers. Analytic expressions of the heat currents in the steady state are spelled out. Asymmetric heat transport is found in this linear system if both the bath temperatures and the temperature-dependent bath-system couplings are exchanged.