Chiral resolution by composite Raman pulses

TL;DR

This paper introduces two composite Raman pulse sequences for efficient and robust chiral molecule detection, significantly improving signal contrast and error tolerance over traditional single-pulse methods.

Contribution

It develops two novel pulse sequence methods for chiral resolution, incorporating composite pulses to enhance robustness and speed compared to existing techniques.

Findings

Composite pulses achieve higher signal contrast.

Methods are more robust to experimental errors.

Two pulse sequence protocols demonstrated for chiral detection.

Abstract

We present two methods for efficient detection of chiral molecules based on sequences of single pulses and Raman pulse pairs. The chiral molecules are modelled by a closed-loop three-state system with different signs in one of the couplings for the two enantiomers. One method uses a sequence of three interaction steps: a single pulse, a Raman pulse, and another single pulse. The other method uses a sequence of only two interaction steps: a Raman pulse, and a single pulse. The second method is simpler and faster but requires a more sophisticated Raman pulse than the first one. Both techniques allow for straightforward generalizations by replacing the single and Raman pulses with composite pulse sequences. The latter achieve very high signal contrast and far greater robustness to experimental errors than by using single pulses. We demonstrate that both constant-rotation (i.e., with phase compensation) and variable-rotation (i.e., with phase distortion) composite pulses can be used, the former being more accurate and the latter being simpler and faster.