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Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
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Bogolon-mediated light absorption in atomic condensates of different dimensionality
Dogyun Ko1,2, Meng Sun3,4, Vadim Kovalev5,6
1Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon, 34126, South Korea. kdg930202@naver.com.
Scientific Reports
|April 19, 2023
Summary
Electromagnetic wave absorption in Bose-Einstein condensates (BECs) is possible for composite bosons with internal structure. This study explores transitions between collective states and excited internal levels, mediated by bogolon excitations.
Area of Science:
- Quantum physics
- Condensed matter physics
- Atomic physics
Background:
- Bose-Einstein condensates (BECs) of structureless bosons typically forbid electromagnetic wave absorption due to conservation laws.
- Collective modes (bogolons) in BECs have phase velocities lower than the speed of light, limiting interactions to light scattering.
Purpose of the Study:
- To develop a microscopic theory for electromagnetic power absorption in Bose-Einstein condensates of cold atoms.
- To investigate absorption mechanisms in composite bosons with internal structure.
- To analyze transitions between collective condensate states and excited internal energy levels of non-condensed atoms.
Main Methods:
- Utilizing the Bogoliubov model for a weakly-interacting Bose gas.
- Developing a microscopic theory to describe electromagnetic power absorption.
- Analyzing transitions mediated by one- and two-bogolon excitations.
Main Results:
- Demonstrated that composite bosons with internal structure can absorb electromagnetic waves.
- Identified one- and two-bogolon excitations as mediators of transitions between collective and internal states.
- Showcased frequency-dependent absorption efficiencies and strong dependence on condensate density and dimensionality.
Conclusions:
- Electromagnetic absorption in BECs is feasible for systems with internal structure, unlike structureless bosons.
- The absorption process is governed by bogolon excitations and sensitive to system parameters like density and dimensionality.
- This work opens avenues for controlling and understanding light-matter interactions in complex quantum systems.
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