Related Experiment Video
Updated: Apr 5, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Complete Quantum State Selectivity in Cold Molecular Beams Using Deflection-Resistant Dark States in a STIRAP
Xuan Li1, Asaf Eilam2, Moshe Shapiro2
1†Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Abstract:
One of the main goals of chemical dynamics is the creation of molecular beams composed of a single (vibrational, rotational, and magnetic) quantum state of choice. In this Letter, we propose a method to achieve complete quantum state selectivity by producing resistance to electromagnetically induced deflection (EID) and that the state to be selected can be "dialed in" at will. We illustrate the method by showing in detail how to purify thermal beams of the LiRb and IF molecules to yield molecular beams composed of a variety of prechosen single internal quantum states and/or superpositions of such states. We expect that this method will be implemented in all subsequent explorations of the fundamentals of chemical reactions and their control and the use of cold molecules as a vehicle for studying some of the most profound issues of quantum dynamics.
Related Concept Videos
Atomic Nuclei: Nuclear Spin State Population Distribution
Atomic Nuclei: Nuclear Spin State Overview
Deactivation Processes: Jablonski Diagram
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...

