scholarly journals Эффективные взаимодействия, индуцированные спин-орбитальной связью в сверхпроводящих нанопроволоках в режиме сильных корреляций

2020 ◽  
Vol 62 (9) ◽  
pp. 1447
Author(s):  
А.О. Злотников ◽  
С.В. Аксенов ◽  
М.С. Шустин
Keyword(s):  
Coupling Parameter ◽  
Coulomb Repulsion ◽  
Open Boundary ◽  
Spin Orbit Coupling ◽  
Edge States ◽  
Open Boundary Conditions ◽  
Strong Electron ◽  
Effective Interactions ◽  
Strong Coulomb ◽  
Superconducting Nanowire

Abstract In the second order of the operator form of the perturbation theory, the effective interactions in a superconducting nanowire have been obtained at the strong electron correlations, when the spin–orbit coupling parameter is comparable with the hopping integral. Using the exact diagonalization technique, in short nanowires with the open boundary conditions at the strong Coulomb repulsion, the excitations corresponding to the Majorana edge states with the energy below the value of a bulk superconducting gap have been demonstrated.

scholarly journals Formation of Majorana fermions in finite-size graphene strips

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Vardan Kaladzhyan ◽  
Cristina Bena
Keyword(s):  
Magnetic Field ◽  
Boundary Conditions ◽  
Finite Size ◽  
Inhomogeneous Magnetic Field ◽  
Orbit Coupling ◽  
Open Boundary ◽  
Majorana Fermions ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Open Boundary Conditions

We investigate the formation of Majorana fermions in finite-size graphene strips with open boundary conditions in both directions, in the presence of an in-plane magnetic field and in the proximity of a superconducting substrate. We show that for long enough strips the Majorana states can form in the presence of a Rashba-like spin-orbit coupling, as well as in the presence of an inhomogeneous magnetic field. We find that, unlike infinite graphene ribbons in which Majorana states arise solely close to the bottom of the band and the Van Hove singularities, for finite-size systems this can happen also at much smaller doping values, close to the Dirac points, and depends strongly on the type of the short edges of the systems (e.g. armchair vs. zigzag), as well as on the width of the ribbons.

scholarly journals Interplay of spin–orbit coupling and Coulomb interaction in ZnO-based electron system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. Maryenko ◽  
M. Kawamura ◽  
A. Ernst ◽  
V. K. Dugaev ◽  
E. Ya. Sherman ◽  
...  
Keyword(s):  
Coulomb Interaction ◽  
High Mobility ◽  
Electron System ◽  
Orbit Coupling ◽  
Electron Interaction ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Strong Electron ◽  
Strongly Coupled ◽  
Dimensional Electron System

AbstractSpin–orbit coupling (SOC) is pivotal for various fundamental spin-dependent phenomena in solids and their technological applications. In semiconductors, these phenomena have been so far studied in relatively weak electron–electron interaction regimes, where the single electron picture holds. However, SOC can profoundly compete against Coulomb interaction, which could lead to the emergence of unconventional electronic phases. Since SOC depends on the electric field in the crystal including contributions of itinerant electrons, electron–electron interactions can modify this coupling. Here we demonstrate the emergence of the SOC effect in a high-mobility two-dimensional electron system in a simple band structure MgZnO/ZnO semiconductor. This electron system also features strong electron–electron interaction effects. By changing the carrier density with Mg-content, we tune the SOC strength and achieve its interplay with electron–electron interaction. These systems pave a way to emergent spintronic phenomena in strong electron correlation regimes and to the formation of quasiparticles with the electron spin strongly coupled to the density.

scholarly journals Impurity induced scale-free localization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Linhu Li ◽  
Ching Hua Lee ◽  
Jiangbin Gong
Keyword(s):  
Boundary Conditions ◽  
Skin Effect ◽  
Reciprocal Lattice ◽  
Periodic Boundary Conditions ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Translational Invariance ◽  
Scale Free ◽  
Special Cases ◽  
Simulation Results

AbstractNon-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning off boundary coupling, a feature very distinct from that under periodic boundary conditions. Here we develop a full framework for non-Hermitian impurity physics in a non-reciprocal lattice, with periodic/open boundary conditions and even their interpolations being special cases across a whole range of boundary impurity strengths. We uncover steady states with scale-free localization along or even against the direction of non-reciprocity in various impurity strength regimes. Also present are Bloch-like states that survive albeit broken translational invariance. We further explore the co-existence of non-Hermitian skin effect and scale-free localization, where even qualitative aspects of the system’s spectrum can be extremely sensitive to impurity strength. Specific circuit setups are also proposed for experimentally detecting the scale-free accumulation, with simulation results confirming our main findings.

Projected sea-level changes in the marginal seas near China based on dynamical downscaling

2021 ◽  
pp. 1-52
Author(s):  
Yi Jin ◽  
Xuebin Zhang ◽  
John A. Church ◽  
Xianwen Bao
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Climate Models ◽  
Dynamical Downscaling ◽  
Global Climate Models ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Sea Level Changes ◽  
Marginal Seas ◽  
The Pacific

AbstractProjections of future sea-level changes are usually based on global climate models (GCMs). However, the changes in shallow coastal regions, like the marginal seas near China, cannot be fully resolved in GCMs. To improve regional sea-level simulations, a high-resolution (~8 km) regional ocean model is set up for the marginal seas near China for both the historical (1994-2015) and future (2079-2100) periods under representative concentration pathways (RCPs) 4.5 and 8.5. The historical ocean simulations are evaluated at different spatiotemporal scales, and the model is then integrated for the future period, driven by projected monthly climatological climate change signals from 8 GCMs individually via both surface and open boundary conditions. The downscaled ocean changes derived by comparing historical and future experiments reveal greater spatial details than those from GCMs, e.g., a low dynamic sea level (DSL) centre of -0.15 m in the middle of the South China Sea (SCS). As a novel test, the downscaled results driven by the ensemble mean forcings are almost identical with the ensemble average results from individually downscaled cases. Forcing of the DSL change and increased cyclonic circulation in the SCS are dominated by the climate change signals from the Pacific, while the DSL change in the East China marginal seas is caused by both local atmosphere forcing and signals from the Pacific. The method of downscaling developed in this study is a useful modelling protocol for adaptation and mitigation planning for future oceanic climate changes.

scholarly journals Ferromagnetism in multiband Hubbard models: From weak to strong Coulomb repulsion

1996 ◽  
Vol 54 (6) ◽  
pp. 4056-4067 ◽  
Author(s):  
Karlo Penc ◽  
Hiroyuki Shiba ◽  
Frédéric Mila ◽  
Takuya Tsukagoshi
Keyword(s):  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Strong Coulomb
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