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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Photon blockade in the ultrastrong coupling regime
1Physik Department, Technische Universität München, James-Franck-Strasse, 85748 Garching, Germany.
Physical Review Letters
|December 11, 2012
Summary
We present new correlation functions for ultrastrong light-matter coupling, modifying photon blockade effects. This reveals parametric processes and oscillations due to two-photon decays in quantum systems.
Area of Science:
- Quantum Optics
- Cavity Quantum Electrodynamics (cQED)
- Strong Light-Matter Interactions
Background:
- The ultrastrong coupling regime, where atom-cavity coupling is comparable to cavity resonance frequency, presents challenges for standard quantum optics descriptions.
- Traditional photon correlation functions are inadequate for characterizing photon statistics under these extreme light-matter interaction conditions.
Purpose of the Study:
- To develop novel correlation functions applicable to arbitrary degrees of light-matter interaction, specifically in the ultrastrong coupling regime.
- To investigate the modifications to fundamental quantum phenomena like photon blockade under ultrastrong coupling.
Main Methods:
- Expressing the electric-field operator in the cavity-emitter dressed basis to handle strong interactions.
- Proposing and analyzing new correlation functions valid beyond the weak coupling approximation.
Main Results:
- Demonstrated significant deviations from the standard photon blockade phenomenon in the ultrastrong coupling regime.
- Observed parametric processes and temporal oscillations in intensity correlation functions, even for simple two-level emitters.
- Attributed these novel effects to two-photon cascade decays driven by counterrotating interaction terms.
Conclusions:
- The proposed correlation functions accurately describe photon statistics in the ultrastrong coupling regime.
- Ultrastrong coupling fundamentally alters quantum optical phenomena, introducing new dynamics like parametric processes and oscillations.
- This work provides a theoretical framework for exploring quantum optics in the previously intractable ultrastrong coupling regime.
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