Model for longitudinal-optical phonons and electron-phonon coupling in GaAs-Ga1−xAlxAs multilayer structures

1991 ◽  
Vol 44 (12) ◽  
pp. 6249-6261 ◽  
Author(s):  
C. Guillemot ◽  
F. Clérot
Keyword(s):  
Longitudinal Optical ◽  
Multilayer Structures ◽  
Optical Phonons ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

Roles of Optical Phonons and Logarithmic Profile of Electron-Phonon Coupling Integration in Superconducting Sc0.5Y0.5H6 Superhydride Under Pressures

2022 ◽  
pp. 163524
Author(s):  
Wiwittawin Sukmas ◽  
Prutthipong Tsuppayakorn-aek ◽  
Udomsilp Pinsook ◽  
Rajeev Ahuja ◽  
Thiti Bovornratanaraks
Keyword(s):  
Optical Phonons ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

scholarly journals Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet CrI3

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wencan Jin ◽  
Hyun Ho Kim ◽  
Zhipeng Ye ◽  
Gaihua Ye ◽  
Laura Rojas ◽  
...  
Keyword(s):  
Magnetic Semiconductors ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Two Dimensional ◽  
Phonon Coupling ◽  
Temperature Dependent ◽  
Strong Electron ◽  
Range Magnetic Order ◽  
Electron Phonon Coupling ◽  
Long Range Magnetic Order

Abstract Exciton dynamics can be strongly affected by lattice vibrations through electron-phonon coupling. This is rarely explored in two-dimensional magnetic semiconductors. Focusing on bilayer CrI3, we first show the presence of strong electron-phonon coupling through temperature-dependent photoluminescence and absorption spectroscopy. We then report the observation of periodic broad modes up to the 8th order in Raman spectra, attributed to the polaronic character of excitons. We establish that this polaronic character is dominated by the coupling between the charge-transfer exciton at 1.96 eV and a longitudinal optical phonon at 120.6 cm−1. We further show that the emergence of long-range magnetic order enhances the electron-phonon coupling strength by ~50% and that the transition from layered antiferromagnetic to ferromagnetic order tunes the spectral intensity of the periodic broad modes, suggesting a strong coupling among the lattice, charge and spin in two-dimensional CrI3. Our study opens opportunities for tailoring light-matter interactions in two-dimensional magnetic semiconductors.

scholarly journals On the Superconductivity Suppression in Eu1−xPrxBa2Cu3O7−δ

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3503
Author(s):  
Paweł Pęczkowski ◽  
Piotr Zachariasz ◽  
Cezariusz Jastrzębski ◽  
Jarosław Piętosa ◽  
Elżbieta Drzymała ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Low Temperature ◽  
Magnetic Moment ◽  
Schematic Diagram ◽  
Optical Phonons ◽  
Phonon Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Phonon Coupling ◽  
X Ray Absorption

This article reports on the non-trivial suppression of superconductivity in the Eu1−xPrxBCO cuprates. As non-magnetic Eu3+ ions are replaced by Pr3+ carrying a magnetic moment, spin-related superconductivity loss can be expected. The research shows that the superconductivity disappearance for x > 0.4 results from depletion of the carriers and their localization. The above conclusion was drawn by low-temperature X-ray diffraction analysis showing increased characteristic phonon frequencies with Pr content. This mechanism should promote electron–phonon coupling, at least for acoustic phonons. However, the inverse phenomenon was detected. Namely, there is a gradual deterioration of the optical phonons responsible for vibration of the Cu–O bonds with Pr increasing, as evidenced by Raman spectroscopy. Furthermore, the results of X-ray absorption spectroscopy precisely showed the location of the carriers for Pr-rich specimens. Finally, a schematic diagram for Eu1−xPrxBCO is proposed to consolidate the presented research.

Optical phonons and electron-phonon coupling in CdS x Se 1-x quantum dots

1995 ◽  
Author(s):  
Vincenzo Spagnolo ◽  
Gaetano Scamarcio ◽  
G. Ventruti ◽  
M. Lugara ◽  
Michele Ferrara ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Phonons ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

scholarly journals Quantum Theory of Multisubband Plasmon– Phonon Coupling

Photonics ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Sofia Ribeiro ◽  
Angela Vasanelli ◽  
Yanko Todorov ◽  
Carlo Sirtori
Keyword(s):  
Longitudinal Optical ◽  
Theoretical Description ◽  
Collective Excitations ◽  
Strong Coupling Regime ◽  
Optical Phonons ◽  
Phonon Coupling ◽  
Dimensional Electron ◽  
Mixed States ◽  
Coupling Energy ◽  
Dimensional Electron Gas

We present a theoretical description of the coupling between longitudinal optical phonons and collective excitations of a two-dimensional electron gas. By diagonalizing the Hamiltonian of the system, including Coulomb electron–electron and Fröhlich interactions, we observe the formation of multisubband polarons, mixed states partially phonon and partially multisubband plasmon, characterized by a coupling energy which is a significant fraction, up to ∼ 40 % , of the phonon energy. We demonstrate that multisubband plasmons and longitudinal optical phonons are in the ultra-strong coupling regime in several III–V and II–VI material systems.

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