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Updated: Jun 6, 2025

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Interplay between classical and quantum dissipation in light-matter dynamics
Facundo Tarasi1, Tchavdar N Todorov2, Carlos M Bustamante3
1Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
This study introduces a quantum-electrodynamics model for electron dynamics interacting with photon and phonon baths. It reveals how semiclassical emission, dependent on coherences, contributes to collective behavior in materials like trans-polyacetylene.
Area of Science:
- Quantum dynamics
- Condensed matter physics
- Quantum electrodynamics
Background:
- Describing electron dynamics in quantum systems requires accounting for energy exchange with photon and phonon baths.
- Existing models often simplify interactions, potentially missing crucial quantum effects.
Purpose of the Study:
- To develop a quantum-electrodynamics (QED) approach for electron dynamics coupled to photon and phonon baths.
- To investigate the role of semiclassical emission within a full QED framework.
- To analyze the response of the Su-Schrieffer-Heeger model in trans-polyacetylene to laser irradiation.
Main Methods:
- Utilizing a dissipative quantum Liouville equation in the Redfield form.
- Incorporating two driving terms for radiative and vibrational relaxation.
- Analyzing the contributions of semiclassical emission and quantum driving terms.
Main Results:
- A QED term was found to replicate semiclassical treatment of dissipated power.
- Semiclassical emission depends on electronic coherences, while other QED terms depend on excited populations.
- The Su-Schrieffer-Heeger model showed stepwise relaxation and subradiant states under pulsed laser excitation.
- Vibrational dissipation led to rapid population of the conduction band minimum and a redshifted emission spectrum.
Conclusions:
- The developed QED approach accurately describes electron dynamics with photon and phonon interactions.
- Semiclassical emission is crucial for understanding collective quantum phenomena.
- Laser irradiation induces distinct relaxation dynamics and spectral shifts depending on pulse characteristics and dissipation mechanisms.
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