Controllable chip-based beam splitter for cold polar molecules

We proposed a Y-shaped molecular beam splitter for guided polar molecules, composed by several 1-μm-thick gold electrodes deposited on a chip. The splitter has a total length of 10 mm and the height of the electrostatic guiding center (minimum of the electric fields) is about 100 μm from the surface of the chip. Our theoretical analysis and trajectory calculations are carried out using two types of polar molecules of ammonia-D3 (ND3) and strontium fluoride (SrF). The calculated results show explicitly that, by applying a few hundred volts on the electrodes, the splitter can direct the guided (light or heavy) polar molecules to either of the two outgoing arms with any desired ratio (from 0% to 100%) by changing the voltages applied on the electrodes. This chip-scale molecular beam splitter offers a platform for molecular optics, precision measurements, and quantum computation. This basic optical element could be integrated into molecular chips and serve as a building block for a future gas-phase molecular laboratory on a chip.