LATTICE DYNAMICS AND ANYON SUPERCONDUCTORS

1990 ◽  
Vol 04 (18) ◽  
pp. 1143-1151 ◽  
Author(s):  
D.M. GAITONDE ◽  
SUMATHI RAO
Keyword(s):  
Magnetic Field ◽  
Gauge Field ◽  
Spectral Function ◽  
Carrier Concentration ◽  
Ground State ◽  
Lattice Dynamics ◽  
Phonon Coupling ◽  
Dominant Effect ◽  
Electron Phonon Coupling ◽  
New Type

We consider a model of anyons—fermions coupled to a statistical gauge field—also coupled to phonons via the usual electron-phonon coupling. We study the phonon response when the system is in the superconducting anyon ground state and show the existence of peaks in the phonon spectral function whose frequencies shift with carrier concentration. We suggest that when the electron-phonon coupling is the dominant effect, there could arise a new type of BCS ground state with a spontaneously generated P and T violating supercurrent, that expels the statistical magnetic field.

Fock approximation to the large polaron in a magnetic field

1976 ◽  
Vol 54 (19) ◽  
pp. 1979-1989 ◽  
Author(s):  
Y. Lepine ◽  
D. Matz
Keyword(s):  
Magnetic Field ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Cylindrical Symmetry ◽  
Coupling Constants ◽  
The Novel ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Large Polaron

We study the large polaron ground state energy in the presence of a constant and uniform magnetic field within the Fock approximation. By use of a new trial spectrum we find a new upper bound to the ground state energy for all magnetic fields and electron–phonon coupling constants. The trial spectrum has the novel feature of keeping cylindrical symmetry for certain values of coupling, even in the absence of magnetic field.

Temperature dependent electron–phonon coupling of Au resolved via lattice dynamics measured with sub-picosecond infrared pulses

2021 ◽  
Vol 129 (19) ◽  
pp. 193104
Author(s):  
John A. Tomko ◽  
Sushant Kumar ◽  
Ravishankar Sundararaman ◽  
Patrick E. Hopkins
Keyword(s):  
Lattice Dynamics ◽  
Phonon Coupling ◽  
Temperature Dependent ◽  
Electron Phonon Coupling

LOW-TEMPERATURE NORMAL-STATE HALL EFFECT IN HIGH-TcBi2Sr2-xLaxCuO6+δ REVEALED BY 60 T MAGNETIC FIELDS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3171-3174
Author(s):  
F. F. BALAKIREV ◽  
J. B. BETTS ◽  
G. S. BOEBINGER ◽  
S. ONO ◽  
Y. ANDO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Normal State ◽  
Ground State ◽  
Low Temperatures ◽  
Optimal Doping ◽  
Underdoped Sample ◽  
Additional Support

We report low-temperature Hall coefficient in the normal state of the high-Tc superconductor Bi 2 Sr 2-x La x CuO 6+δ. The Hall coefficient was measured down to 0.5 K by suppressing superconductivity with a 60 T pulsed magnetic field. The carrier concentration was varied from overdoped to underdoped regimes by partially substituting Sr with La in a set of five samples. The observed saturation of the Hall coefficient at low temperatures suggests the ability to extract the carrier concentration of each sample. The most underdoped sample exhibits a diverging Hall coefficient at low temperatures, consistent with a depletion of carriers in the insulating ground state. The Hall number exhibits a sharp peak providing additional support for the existence of a phase boundary at the optimal doping.

scholarly journals Acoustic phonon lifetimes limit thermal transport in methylammonium lead iodide

2018 ◽  
Vol 115 (47) ◽  
pp. 11905-11910 ◽  
Author(s):  
Aryeh Gold-Parker ◽  
Peter M. Gehring ◽  
Jonathan M. Skelton ◽  
Ian C. Smith ◽  
Dan Parshall ◽  
...  
Keyword(s):  
Lattice Dynamics ◽  
Acoustic Phonon ◽  
Optoelectronic Devices ◽  
High Energy ◽  
High Energy Resolution ◽  
Phonon Coupling ◽  
Lead Iodide ◽  
Phonon Modes ◽  
Electron Phonon Coupling ◽  
Methylammonium Lead Iodide

Hybrid organic–inorganic perovskites (HOIPs) have become an important class of semiconductors for solar cells and other optoelectronic applications. Electron–phonon coupling plays a critical role in all optoelectronic devices, and although the lattice dynamics and phonon frequencies of HOIPs have been well studied, little attention has been given to phonon lifetimes. We report high-precision momentum-resolved measurements of acoustic phonon lifetimes in the hybrid perovskite methylammonium lead iodide (MAPI), using inelastic neutron spectroscopy to provide high-energy resolution and fully deuterated single crystals to reduce incoherent scattering from hydrogen. Our measurements reveal extremely short lifetimes on the order of picoseconds, corresponding to nanometer mean free paths and demonstrating that acoustic phonons are unable to dissipate heat efficiently. Lattice-dynamics calculations using ab initio third-order perturbation theory indicate that the short lifetimes stem from strong three-phonon interactions and a high density of low-energy optical phonon modes related to the degrees of freedom of the organic cation. Such short lifetimes have significant implications for electron–phonon coupling in MAPI and other HOIPs, with direct impacts on optoelectronic devices both in the cooling of hot carriers and in the transport and recombination of band edge carriers. These findings illustrate a fundamental difference between HOIPs and conventional photovoltaic semiconductors and demonstrate the importance of understanding lattice dynamics in the effort to develop metal halide perovskite optoelectronic devices.

scholarly journals Elusive electron-phonon coupling in quantitative analyses of the spectral function

2010 ◽  
Vol 82 (1) ◽  
Author(s):  
C. N. Veenstra ◽  
G. L. Goodvin ◽  
M. Berciu ◽  
A. Damascelli
Keyword(s):  
Spectral Function ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Quantitative Analyses

A First-Principles Study of Electron-Phonon Coupling of OsB2

2014 ◽  
Vol 597 ◽  
pp. 113-116
Author(s):  
Yue Qin Wang ◽  
Juan Gao ◽  
Shao Ping Yan
Keyword(s):  
Transition Temperature ◽  
First Principles ◽  
Linear Response ◽  
Lattice Dynamics ◽  
Superhard Material ◽  
Superconducting Transition ◽  
Phonon Coupling ◽  
Phonon Modes ◽  
Electron Phonon Coupling ◽  
Coulomb Pseudopotential

We investigated the lattice dynamics and electron-phonon coupling (EPC) of superhard material OsB2by first-principles linear response calculations. The calculated EPC parameters for the optical phonon modes at Г indicate that the heavy Os atoms play the most important role in deciding the superconducting behavior, and there are sizeable contributions from lighter B atoms to EPC. Our calculated EPC constant is 0.42, and the estimated superconducting transition temperatureTcis 2.1 K using the Coulomb pseudopotentialμ*=0.125, in excellent agreement with the experimental ones.

Interchain Alignments and Ground State in Organic Ferromagnets

1998 ◽  
Vol 12 (28) ◽  
pp. 1167-1174
Author(s):  
W. Z. Wang ◽  
K. L. Yao ◽  
H. Q. Lin
Keyword(s):  
Spin Density ◽  
Ground State ◽  
Main Chain ◽  
Phonon Coupling ◽  
Structure Transition ◽  
Interchain Coupling ◽  
Ferromagnetic Structure ◽  
Phase Alignment ◽  
Electron Phonon Coupling ◽  
Organic Ferromagnets

Two kinds of alignments of two neighboring π-conjugated organic ferromagnetic chains are studied by considering the itinerary of electrons, electron–phonon coupling, the Hubbard repulsion and the interchain coupling. It is shown that the out-of-phase alignment is a more stable ferromagnetic structure than in-phase alignment. For out-of-phase alignment, there is a structure transition at a critical interchain coupling, at which the dimerizations of two chains have the same size and reverse sign. Interchain coupling results in transfer of spin density between each main chain and the side radicals.

Extraordinary role of Zn in enhancing thermoelectric performance of Ga-doped n-type PbTe

2022 ◽  
Author(s):  
Zhong-zhen Luo ◽  
Songting Cai ◽  
Shiqiang Hao ◽  
Trevor Bailey ◽  
Yubo Luo ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Lattice Thermal Conductivity ◽  
Thermoelectric Performance ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Ga Doping ◽  
Role Of Zn

Although Ga doping can weaken the electron phonon coupling of n-type PbTe, Ga-doped PbTe has a relatively low carrier concentration (n) and high lattice thermal conductivity (κlat), resulting in a...

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