scholarly journals Hydrogen-molecule spectrum by the many-body GW approximation and the Bethe-Salpeter equation

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Jing Li ◽  
Valerio Olevano
Keyword(s):  
Hydrogen Molecule ◽  
Many Body ◽  
Gw Approximation ◽  
The Many

scholarly journals Towards quantitative accuracy in first-principles transport calculations: The GW method applied to alkane/gold junctions

2011 ◽  
Vol 2 ◽  
pp. 746-754 ◽  
Author(s):  
Mikkel Strange ◽  
Kristian S Thygesen
Keyword(s):  
Dft Calculations ◽  
First Principles ◽  
Density Functional ◽  
Energy Levels ◽  
Many Body ◽  
Gw Approximation ◽  
Quantitative Accuracy ◽  
Dynamic Screening ◽  
Electronic Conductance ◽  
The Many

The calculation of the electronic conductance of nanoscale junctions from first principles is a long-standing problem in the field of charge transport. Here we demonstrate excellent agreement with experiments for the transport properties of the gold/alkanediamine benchmark system when electron–electron interactions are described by the many-body GW approximation. The conductance follows an exponential length dependence: G n = G c exp(−βn). The main difference from standard density functional theory (DFT) calculations is a significant reduction of the contact conductance, G c , due to an improved alignment of the molecular energy levels with the metal Fermi energy. The molecular orbitals involved in the tunneling process comprise states delocalized over the carbon backbone and states localized on the amine end groups. We find that dynamic screening effects renormalize the two types of states in qualitatively different ways when the molecule is inserted in the junction. Consequently, the GW transport results cannot be mimicked by DFT calculations employing a simple scissors operator.

On the many-body theory of nuclear reactions

1968 ◽  
Vol 111 (1) ◽  
pp. 392-416 ◽  
Author(s):  
K DIETRICH ◽  
K HARA
Keyword(s):  
Nuclear Reactions ◽  
Many Body ◽  
Many Body Theory ◽  
The Many ◽  
Body Theory

Revealing the many-body interactions and valley-polarization behavior in Re-doped MoS2 monolayers

2021 ◽  
Vol 118 (11) ◽  
pp. 113101
Author(s):  
Xiaoli Zhu ◽  
Siting Ding ◽  
Lihui Li ◽  
Ying Jiang ◽  
Biyuan Zheng ◽  
...  
Keyword(s):  
Many Body ◽  
Polarization Behavior ◽  
Valley Polarization ◽  
Mos2 Monolayers ◽  
The Many ◽  
Many Body Interactions

scholarly journals Entangling Lattice-Trapped Bosons with a Free Impurity: Impact on Stationary and Dynamical Properties

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 290
Author(s):  
Maxim Pyzh ◽  
Kevin Keiler ◽  
Simeon I. Mistakidis ◽  
Peter Schmelcher
Keyword(s):  
Structural Changes ◽  
Many Body ◽  
Wide Range ◽  
Entropy Measures ◽  
Particle Level ◽  
The Many ◽  
The One ◽  
Tunneling Dynamics ◽  
The Individual ◽  
Trapped Bosons

We address the interplay of few lattice trapped bosons interacting with an impurity atom in a box potential. For the ground state, a classification is performed based on the fidelity allowing to quantify the susceptibility of the composite system to structural changes due to the intercomponent coupling. We analyze the overall response at the many-body level and contrast it to the single-particle level. By inspecting different entropy measures we capture the degree of entanglement and intraspecies correlations for a wide range of intra- and intercomponent interactions and lattice depths. We also spatially resolve the imprint of the entanglement on the one- and two-body density distributions showcasing that it accelerates the phase separation process or acts against spatial localization for repulsive and attractive intercomponent interactions, respectively. The many-body effects on the tunneling dynamics of the individual components, resulting from their counterflow, are also discussed. The tunneling period of the impurity is very sensitive to the value of the impurity-medium coupling due to its effective dressing by the few-body medium. Our work provides implications for engineering localized structures in correlated impurity settings using species selective optical potentials.

scholarly journals On the Many-Body Expansion of an Interaction Energy of Some Supramolecular Halogen-Containing Capsules

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4431
Author(s):  
Jiří Czernek ◽  
Jiří Brus
Keyword(s):  
Density Functional ◽  
Condensed Phases ◽  
Multicomponent Mixtures ◽  
Many Body ◽  
Symmetric Form ◽  
Functional Theory ◽  
Emergent Features ◽  
The Many ◽  
Surprising Fact ◽  
Dimethyl Benzene

A tetramer model was investigated of a remarkably stable iodine-containing supramolecular capsule that was most recently characterized by other authors, who described emergent features of the capsule’s formation. In an attempt to address the surprising fact that no strong pair-wise interactions between any of the respective components were experimentally detected in condensed phases, the DFT (density-functional theory) computational model was used to decompose the total stabilization energy as a sum of two-, three- and four-body contributions. This model considers complexes formed between either iodine or bromine and the crucial D4h-symmetric form of octaaryl macrocyclic compound cyclo[8](1,3-(4,6-dimethyl)benzene that is surrounded by arenes of a suitable size, namely, either corannulene or coronene. A significant enthalpic gain associated with the formation of investigated tetramers was revealed. Furthermore, it is shown that the total stabilization of these complexes is dominated by binary interactions. Based on these findings, comments are made regarding the experimentally observed behavior of related multicomponent mixtures.

scholarly journals Mechanisms of electron-phonon coupling unraveled in momentum and time: The case of soft phonons in TiSe2

2021 ◽  
Vol 7 (20) ◽  
pp. eabf2810
Author(s):  
Martin R. Otto ◽  
Jan-Hendrik Pöhls ◽  
Laurent P. René de Cotret ◽  
Mark J. Stern ◽  
Mark Sutton ◽  
...  
Keyword(s):  
Wave Vector ◽  
Density Wave ◽  
Phonon Coupling ◽  
Many Body ◽  
Soft Zone ◽  
Electron Phonon Coupling ◽  
Underlying Mechanisms ◽  
The Many ◽  
Coupling Phenomena ◽  
Electron Pocket

The complex coupling between charge carriers and phonons is responsible for diverse phenomena in condensed matter. We apply ultrafast electron diffuse scattering to unravel electron-phonon coupling phenomena in 1T-TiSe2 in both momentum and time. We are able to distinguish effects due to the real part of the many-body bare electronic susceptibility, R[χ0(q)], from those due to the electron-phonon coupling vertex, gq, by following the response of semimetallic (normal-phase) 1T-TiSe2 to the selective photo-doping of carriers into the electron pocket at the Fermi level. Quasi-impulsive and wave vector–specific renormalization of soft zone-boundary phonon frequencies (stiffening) is observed, followed by wave vector–independent electron-phonon equilibration. These results unravel the underlying mechanisms driving the phonon softening that is associated with the charge density wave transition at lower temperatures.

scholarly journals The Superconducting Critical Temperature

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 911
Author(s):  
Mike Guidry ◽  
Yang Sun ◽  
Lian-Ao Wu
Keyword(s):  
Critical Temperature ◽  
Dynamical Symmetry ◽  
Many Body ◽  
Unconventional Superconductors ◽  
The Many ◽  
Pair Coupling ◽  
Intrinsic Strength ◽  
Superconducting Transitions

Two principles govern the critical temperature for superconducting transitions: (1) intrinsic strength of the pair coupling and (2) the effect of the many-body environments on the efficiency of that coupling. Most discussions take into account only the former, but we argue that the properties of unconventional superconductors are governed more often by the latter, through dynamical symmetry relating to normal and superconducting states. Differentiating these effects is essential to charting a path to the highest-temperature superconductors.

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