Magneto-Optical Properties of Paramagnetic Superrotors

Area of Science:

• Molecular dynamics
• Quantum mechanics
• Spectroscopy

Background:

• Paramagnetic molecules can be prepared in highly excited rotational states using optical centrifuges.
• Understanding molecular behavior in external fields is crucial for controlling quantum systems.

Purpose of the Study:

• To investigate the dynamics of paramagnetic molecular superrotors in an external magnetic field.
• To explore the phenomenon of magneto-rotational birefringence in oxygen molecules.

Main Methods:

• Utilizing an optical centrifuge to create dense ensembles of oxygen molecules in ultrahigh rotational states.
• Applying an external magnetic field to observe changes in optical properties.
• Employing direct imaging of molecular axis distribution and rotational Raman spectroscopy.

Main Results:

• Demonstrated for the first time that a gas of rotating molecules becomes optically birefringent in a magnetic field.
• Observed preferential alignment of molecular axes along the magnetic field direction.
• Confirmed the role of spin-rotation coupling in mediating the magnetic field's influence on molecular orientation.

Conclusions:

• The study reveals a novel effect, magneto-rotational birefringence, in paramagnetic molecular superrotors.
• The findings provide insights into the interplay between molecular rotation, spin, and external magnetic fields.
• The developed qualitative model, supported by experimental and numerical evidence, explains the observed phenomena.