Driving rotational transitions in molecules on a chip

TL;DR

This paper demonstrates inducing and controlling rotational state transitions in molecules on a chip using narrow-band mm-wave radiation, enabling precise manipulation of molecules in quantum states for potential quantum technologies.

Contribution

It introduces a method to induce and control rotational transitions in molecules on a chip using mm-wave radiation, combining spectroscopy and molecule guiding techniques.

Findings

Successful coupling of mm-wave radiation to molecules near the chip

Demonstration of rotational transition induction on-chip

Guiding molecules before and after state transition

Abstract

Polar molecules in selected quantum states can be guided, decelerated, and trapped using electric fields created by microstructured electrodes on a chip. Here we explore how transitions between two of these quantum states can be induced while the molecules are on the chip. We use CO (a 3-Pi(1), v=0) molecules, prepared in the J=1 rotational level, and induce the J=2 <-- J=1 rotational transition with narrow-band sub-THz (mm-wave) radiation. First, the mm-wave source is characterized using CO molecules in a freely propagating molecular beam, and both Rabi cycling and rapid adiabatic passage are examined. Then, we demonstrate that the mm-wave radiation can be coupled to CO molecules that are less than 50 micron above the chip. Finally, CO molecules are guided in the J=1 level to the center of the chip where they are pumped to the J=2 level, recaptured, and guided off the chip.