scholarly journals Electronic perturbation effects in the presence of electric field for π‐conjugated systems: An electron‐correlation study

2020 ◽  
Vol 120 (16) ◽  
Author(s):  
Anton B. Zakharov ◽  
Vladimir V. Ivanov ◽  
Ludwik Adamowicz
Keyword(s):  
Electric Field ◽  
Electron Correlation ◽  
Correlation Study ◽  
Conjugated Systems ◽  
Electronic Perturbation

scholarly journals Quantum anomalous Hall effect from intertwined moiré bands

2021 ◽  
Author(s):  
Kin Fai Mak ◽  
Tingxin Li ◽  
Shengwei Jiang ◽  
Bowen Shen ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Electric Field ◽  
Electron Correlation ◽  
Anomalous Hall Effect ◽  
Mott Insulator ◽  
Zero Magnetic Field ◽  
Hall Resistance ◽  
High Symmetry ◽  
Topological Phase ◽  
Wigner Crystals ◽  
And Topology

Abstract Electron correlation and topology are two central threads of modern condensed matter physics. Semiconductor moiré materials provide a highly tunable platform for studies of electron correlation. Correlation-driven phenomena, including the Mott insulator, generalized Wigner crystals, stripe phases and continuous Mott transition, have been demonstrated. However, nontrivial band topology has remained elusive. Here we report the observation of a quantum anomalous Hall (QAH) effect in AB-stacked MoTe2/WSe2 moiré heterobilayers. Unlike in the AA-stacked structures, an out-of-plane electric field controls not only the bandwidth but also the band topology by intertwining moiré bands centered at different high-symmetry stacking sites. At half band filling, corresponding to one particle per moiré unit cell, we observe quantized Hall resistance, h/e^2 (with h and e denoting the Planck’s constant and electron charge, respectively), and vanishing longitudinal resistance at zero magnetic field. The electric-field-induced topological phase transition from a Mott insulator to a QAH insulator precedes an insulator-to-metal transition; contrary to most known topological phase transitions, it is not accompanied by a bulk charge gap closure. Our study paves the path for discovery of a wealth of emergent phenomena arising from the combined influence of strong correlation and topology in semiconductor moiré materials.

Time-differential perturbed-angular-correlation study of the electric field gradient in amorphousZr68Hf2Cu30

1986 ◽  
Vol 34 (4) ◽  
pp. 2982-2984 ◽  
Author(s):  
L. A. Mendoza-Zélis ◽  
L. C. Damonte ◽  
A. G. Bibiloni ◽  
J. Desimoni ◽  
A. R. López-García
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Correlation Study ◽  
Time Differential

An ab initio Study of the Molecular Electric-field Gradients of the Chlorsilanes

1996 ◽  
Vol 51 (1-2) ◽  
pp. 41-45
Author(s):  
H. U. Suter ◽  
D. M. Maric ◽  
P. F. Meier
Keyword(s):  
Electric Field ◽  
Ab Initio ◽  
Electron Correlation ◽  
Basis Sets ◽  
Quadrupole Moments ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Extended Basis ◽  
Good Agreement ◽  
Nuclear Quadrupole Moments

Abstract The electric field gradient (EFG) of chlorine in the chlorine containing silanes (SiCl4 , SiCl3H, SiCl2H2 , and SiClH3) was determined by means of ab initio methods and compared to recent experiments from which nuclear quadrupole moments are extracted. A careful estimation of the AO basis sets and the effect of the electron correlation is undertaken. The results showed the importance of the use of extended basis sets in the calculation of EFGs in second row atoms. Good agreement with deviations less than 5% from the experiments was found. The effect of the electron correlation was found to be small.

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