J. Phys. B 51, 135005 (2018)

Trapping cold atoms near a solid surface induces the kind of coupling required to build hybrid quantum devices. And introducing plasmonic surfaces into the mix can increase the strength of this coupling still further. Now, Matthias Mildner and colleagues have come up with a new trap design that uses a thin gold layer to exploit and control this plasmonic enhancement. The team has presented a numerical characterization of their proposed trap, together with a first test structure.

The working principle is based on two overlapping evanescent waves that are both plasmonically enhanced: one wave with red detuning gives rise to an attractive surface potential, while the other has blue detuning that induces a repulsive surface potential. By manipulating the local thickness of the gold layer in their simulations, Mildner and co-workers showed that they could modulate the depth of the trap. Exploiting this level of control should enable the generation of non-periodic potential landscapes — including heterostructures with custom-designed defects.