Precisely spun super rotors

Area of Science:

• Quantum optics and molecular physics
• Precision measurement and quantum information science

Background:

• Optical control of molecular quantum states is crucial for quantum chemistry, fundamental physics tests, and quantum information processing.
• While ground state preparation is common, excited molecular states offer unique research opportunities.

Purpose of the Study:

• To demonstrate a broadband optical method for preparing pure ensembles of trapped silicon monoxide ions (SiO+) in highly excited rotational states (super rotors).
• To utilize these super rotors for novel spectroscopic investigations and probing of molecular structure.

Main Methods:

• Broadband optical pumping of trapped SiO+ molecules.
• Preparation of super rotor ensembles with narrow rotational state distributions.
• Spectroscopic analysis of the SiO+ C2Π state and investigation of centrifugal distortion effects.

Main Results:

• Achieved pure super rotor ensembles of SiO+ maintained for minutes, pumped to rotational states up to N=67 (equivalent to 9400 K).
• Observed narrow rotational state spread in super rotors, comparable to cryogenic samples.
• Performed spectroscopy of the previously unobserved C2Π state of SiO+.
• Probed SiO+ electronic structure at significantly stretched bond lengths (up to N=230) due to centrifugal distortion.

Conclusions:

• Broadband optical pumping is an effective method for creating well-defined, highly excited molecular rotational states.
• Super rotor ensembles provide a powerful platform for high-resolution spectroscopy and exploring molecular behavior under extreme conditions.
• This work opens new avenues for quantum control of molecules and fundamental studies of electronic structure.