scholarly journals Cavity quantum-electrodynamical polaritonically enhanced electron-phonon coupling and its influence on superconductivity

2018 ◽  
Vol 4 (11) ◽  
pp. eaau6969 ◽  
Author(s):  
M. A. Sentef ◽  
M. Ruggenthaler ◽  
A. Rubio
Keyword(s):  
Forward Scattering ◽  
Phonon Coupling ◽  
Superconducting Properties ◽  
Pairing Mechanism ◽  
Pump Probe ◽  
Matter Coupling ◽  
Mode Softening ◽  
Electron Phonon Coupling ◽  
Laser Control ◽  
Low Dimensional

So far, laser control of solids has been mainly discussed in the context of strong classical nonlinear light-matter coupling in a pump-probe framework. Here, we propose a quantum-electrodynamical setting to address the coupling of a low-dimensional quantum material to quantized electromagnetic fields in quantum cavities. Using a protoypical model system describing FeSe/SrTiO3with electron-phonon long-range forward scattering, we study how the formation of phonon polaritons at the two-dimensional interface of the material modifies effective couplings and superconducting properties in a Migdal-Eliashberg simulation. We find that through highly polarizable dipolar phonons, large cavity-enhanced electron-phonon couplings are possible, but superconductivity is not enhanced for the forward-scattering pairing mechanism due to the interplay between coupling enhancement and mode softening. Our results demonstrate that quantum cavities enable the engineering of fundamental couplings in solids, paving the way for unprecedented control of material properties.

Structural distortion and electronic states of Rb doped WO3 by X-ray absorption spectroscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (109) ◽  
pp. 107871-107877 ◽  
Author(s):  
Y. C. Wang ◽  
C. H. Hsu ◽  
Y. Y. Hsu ◽  
C. C. Chang ◽  
C. L. Dong ◽  
...  
Keyword(s):  
Structural Phase ◽  
Electronic States ◽  
Phonon Coupling ◽  
Structural Phase Transitions ◽  
Superconducting Properties ◽  
Strong Electron ◽  
X Ray ◽  
Electron Phonon Coupling ◽  
Complex Structural ◽  
X Ray Absorption

Rubidium tungsten bronzes (RbxWO3) have recently attracted much attention due to their intriguing phenomena, such as complex structural phase transitions, strong electron–phonon coupling, and superconducting properties.

scholarly journals Forward Electron–Phonon Scattering in Normal and Superconducting States

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3083-3086 ◽  
Author(s):  
O. V. Dolgov ◽  
O. V. Danylenko ◽  
M. L. Kulić ◽  
V. Oudovenko
Keyword(s):  
Critical Temperature ◽  
Density Of States ◽  
Phonon Scattering ◽  
Phonon Frequency ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Superconducting Properties ◽  
Electron Phonon Coupling ◽  
D Wave ◽  
Electron Phonon Scattering

The sharp forward electron–phonon (FEP) and impurity (FIS) scattering change the normal and superconducting properties significantly. The pseudo-gap like features are present in the density of states for ω<Ω, where Ω is the phonon frequency. The superconducting critical temperature T c , due to the FEP pairing, is linear with respect to the electron–phonon coupling constant. The FIS impurities are pair weakening for s- and d-wave pairing.

Mechanisms of high-Tc superconductivity in low-dimensional materials

1987 ◽  
Vol 2 (6) ◽  
pp. 793-799 ◽  
Author(s):  
Vladimir Z. Kresin
Keyword(s):  
Proximity Effect ◽  
Coherence Length ◽  
Two Dimensional ◽  
Phonon Coupling ◽  
Strong Electron ◽  
High Tc ◽  
Electron Phonon Coupling ◽  
Low Dimensionality ◽  
Low Dimensional ◽  
Low Dimensional Materials

High-Tc superconductivity is due to the action of two mechanisms: (1) plasmon mechanism, i.e., exchange of two-dimensional (2-D) plasmons and (2) strong electron-phonon coupling. The low dimensionality and the small value of the carrier concentration make the plasmon mechanism favorable. The small value of the coherence length leads to a unique opportunity to observe a multigap structure. The proximity effect can be used in order to increase Tc of A-15 compounds.

Oxides: An answer to the qubit problem?

2019 ◽  
Vol 33 (14) ◽  
pp. 1930003
Author(s):  
Amit Dey ◽  
Sudhakar Yarlagadda
Keyword(s):  
Electronic Devices ◽  
Small Scale ◽  
Double Quantum ◽  
Phonon Coupling ◽  
Many Body ◽  
Double Quantum Dots ◽  
Electron Phonon Coupling ◽  
Low Dimensional ◽  
And Control ◽  
Many Body Interactions

Low-dimensional complex oxides offer new opportunities for small-scale electronic devices where diverse spin, charge and orbital correlations can be suitably adapted by manipulating many-body interactions, geometries, disorder, fields, strain, etc. Therefore, oxides may be viewed as one of the promising candidates for replacing semiconductors in future devices. Maintaining coherence and control in a qubit is an important necessity for quantum computation. In this review, we discuss an example of oxide devices: decoherence-free oxide-based qubits. We present recent progress in demonstrating that long coherence times can be achieved at easily accessible temperatures in charge qubits of oxide double quantum dots. For treating strong coupling to the environment, we describe a nonperturbative approach that is useful for oxides. We illustrate ways to enhance the coherence times: increasing the electron–phonon coupling, detuning the dots to a fraction of the optical phonon energy, decreasing the temperature or reducing the adiabaticity.

scholarly journals Monitoring hot exciton dissociation in hybrid lead halide perovskite films with sub-10 fs pulses

2019 ◽  
Vol 205 ◽  
pp. 06019
Author(s):  
Tufan Ghosh ◽  
Sigalit Aharon ◽  
Lioz Etgar ◽  
Sanford Ruhman
Keyword(s):  
Optical Band Gap ◽  
Phonon Coupling ◽  
Exciton Dissociation ◽  
Pump Probe ◽  
Spectral Modulation ◽  
Coherent Wave ◽  
Electron Phonon Coupling ◽  
Weak Regime ◽  
Coupling Strengths ◽  
Lead Halide

Sub-10 fs pump-probe experiments on methylammonium lead halide (MAPbI3) perovskite films show hot exciton dissociation in 20 fs after photo-excitation with ~0.7 eV excess energy compared to its optical band gap (BG). Coherent wave packets were also detected in the form of spectral modulation, revealing electron-phonon coupling in these materials. The estimated electron-phonon coupling strengths from the frequency and amplitude of the detected spectral modulation are in the weak regime, suggesting formation of large polaron.

scholarly journals EPW: Electron–phonon coupling, transport and superconducting properties using maximally localized Wannier functions

2016 ◽  
Vol 209 ◽  
pp. 116-133 ◽  
Author(s):  
S. Poncé ◽  
E.R. Margine ◽  
C. Verdi ◽  
F. Giustino
Keyword(s):  
Phonon Coupling ◽  
Superconducting Properties ◽  
Wannier Functions ◽  
Electron Phonon Coupling

scholarly journals Electron-phonon coupling and pairing mechanism in β−Bi2Pd centrosymmetric superconductor

2017 ◽  
Vol 95 (1) ◽  
Author(s):  
Jing-Jing Zheng ◽  
E. R. Margine
Keyword(s):  
Phonon Coupling ◽  
Pairing Mechanism ◽  
Electron Phonon Coupling

Electron-Phonon Coupling in Low Dimensional Organic Superconductors

1993 ◽  
Vol 234 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Danilo Pedron ◽  
Renato Bozio ◽  
Moreno Meneghetti ◽  
Cesare Pecile
Keyword(s):  
Organic Superconductors ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Low Dimensional

Thermopower of low-dimensional structures: The effect of electron–phonon coupling

2017 ◽  
Author(s):  
M. Tsaousidou
Keyword(s):  
Quantum Wires ◽  
Single Wall Carbon Nanotubes ◽  
Two Dimensional ◽  
Phonon Drag ◽  
Phonon Coupling ◽  
Electron Gases ◽  
Theoretical Approaches ◽  
Electron Phonon Coupling ◽  
Low Dimensional

This article examines the effect of electron-phonon coupling on the thermopower of low-dimensional structures. It begins with a review of the theoretical approaches and the basic concepts regarding phonon drag under different transport regimes in two- and one-dimensional systems. It then considers the thermopower of two-dimensional semiconductor structures, focusing on phonon drag in semi-classical two-dimensional electron gases confined in semiconductor nanostructures. It also analyzes the influence of phonon drag on the thermopower of semiconductor quantum wires and describes the phonon-drag thermopower of doped single-wall carbon nanotubes. The article compares theory and experiment in order to demonstrate the role of phonon-drag and electron-phonon coupling in the thermopower in two and one dimensions.

NON-LINEARITY AND ANISOTROPY OF ELECTRON-PHONON COUPLING IN HIGH-Tc OXIDES

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3566-3568 ◽  
Author(s):  
G. Santi ◽  
T. Jarlborg
Keyword(s):  
Fermi Surface ◽  
Transport Properties ◽  
Electronic Structures ◽  
Forward Scattering ◽  
Phonon Coupling ◽  
High Tc ◽  
Electron Phonon Coupling ◽  
Large Distortion ◽  
Lattice Distortions ◽  
D Wave

The calculated electronic structures of YBa 2 Cu 3 O 7, HgBa 2 CuO 4 and Bi 2 Sr 2 CaCu 2 O 8 are found to be sensitive to lattice distortions. For large distortion amplitudes of some modes, the calculations show that the electron-phonon coupling (λ) will be much enhanced, so that the coupling behaves non-linearly with the distortion. The c-axis transport properties vary with the distortion from being almost insulating and thereby weakly screened, to being more conducting with rather metallic screening. The calculated anisotropy λ(k,k′) over the Fermi surface (FS) of the Hg-compound, is found to be of "forward scattering" type, which is favorable for d-wave superconductivity.

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