Topological Charges of Periodically Kicked Molecules.
Volker Karle1, Areg Ghazaryan1, Mikhail Lemeshko1
1Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
Physical Review Letters
|March 24, 2023
Summary
Simple molecules driven by laser pulses exhibit topological charges, analogous to solid-state physics. This discovery opens avenues for controllable topological physics in molecular systems.
Area of Science:
- Quantum physics
- Molecular physics
- Condensed matter physics
Background:
- Molecules can exhibit complex behaviors when subjected to external fields.
- Topological concepts, originating from condensed matter physics, offer unique ways to characterize states of matter.
Purpose of the Study:
- To investigate the emergence of topological charges in simple molecules under laser driving.
- To establish an analogy between molecular dynamics and solid-state band structures.
Main Methods:
- Driving closed-shell diatomic molecules with periodic far-off-resonant laser pulses.
- Mapping the molecular rotor dynamics onto a crystalline lattice in angular momentum space.
- Defining quasimomenta and band structure in the Floquet representation.
Main Results:
- Discovery of Dirac cones with topological charges in a synthetic dimension of laser strength.
- Topological protection of Dirac cones by reflection and time-reversal symmetry.
- Broad tunability of topological features by adjusting laser strength.
Conclusions:
- Simple molecules can host topological charges, enabling the study of topological physics in gas-phase experiments.
- This work provides a new framework for classifying dynamical molecular states using topological invariants.
- The findings bridge molecular physics and topological quantum matter, with potential for experimental verification.
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