Controlling electronic spin relaxation of cold molecules with electric fields

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Chemical Physics

Background:

• Molecular spin relaxation is crucial for understanding chemical dynamics and controlling molecular behavior.
• Low-temperature environments (below 0.5 K) are essential for observing subtle quantum effects in molecular systems.
• Zeeman transitions, influenced by magnetic fields, play a role in molecular energy level structures.

Purpose of the Study:

• To theoretically investigate the control of electronic spin relaxation in molecules using superimposed electric and magnetic fields.
• To explore the mechanism by which electric fields can manipulate Zeeman transitions.
• To assess the potential impact of these field-controlled dynamics on chemical reactions and molecular cooling.

Main Methods:

• Theoretical modeling of atom-molecule collisions in combined electric and magnetic fields.
• Analysis of intramolecular spin-rotation couplings and molecule-field interactions.
• Quantum dynamical simulations to study nonadiabatic spin transitions.

Main Results:

• Demonstrated that the strength and orientation of superimposed electric and magnetic fields can precisely control molecular spin relaxation dynamics below 0.5 K.
• Elucidated the mechanism of electric field control over Zeeman transitions, involving a complex interplay of spin-rotation and molecule-field interactions.
• Identified that electric fields can induce nonadiabatic spin transitions, potentially altering chemical reaction pathways.

Conclusions:

• Superimposed electric and magnetic fields offer a powerful tool for manipulating molecular spin dynamics at cryogenic temperatures.
• The proposed mechanism provides a pathway to control chemical reactions by influencing electronic spin states.
• Electric field-induced spin transitions can facilitate evaporative cooling of molecules trapped in magnetic fields, advancing sympathetic cooling techniques.