Critical topological nodal points and nodal lines/rings in Kagome graphene

2020 ◽  
Vol 22 (16) ◽  
pp. 8713-8718
Author(s):  
Jun Zhou ◽  
Yuee Xie ◽  
Shengbai Zhang ◽  
Yuanping Chen
Keyword(s):  
Transport Phenomena ◽  
Topological Phases ◽  
Topological Properties ◽  
Many Body ◽  
Body Effect ◽  
Nodal Lines ◽  
Flat Bands ◽  
Nodal Points

Critical topological phases, possessing flat bands, provide a platform to study unique topological properties and transport phenomena under a many-body effect.

scholarly journals The bulk-corner correspondence of time-reversal symmetric insulators

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Sander Kooi ◽  
Guido van Miert ◽  
Carmine Ortix
Keyword(s):  
Time Reversal ◽  
Real Space ◽  
Topological Phases ◽  
Spin Orbit Coupling ◽  
Topological Properties ◽  
Many Body ◽  
Boundary Correspondence ◽  
Berry Phases ◽  
The Many ◽  
Do So

AbstractThe topology of insulators is usually revealed through the presence of gapless boundary modes: this is the so-called bulk-boundary correspondence. However, the many-body wavefunction of a crystalline insulator is endowed with additional topological properties that do not yield surface spectral features, but manifest themselves as (fractional) quantized electronic charges localized at the crystal boundaries. Here, we formulate such bulk-corner correspondence for the physical relevant case of materials with time-reversal symmetry and spin-orbit coupling. To do so we develop partial real-space invariants that can be neither expressed in terms of Berry phases nor using symmetry-based indicators. These previously unknown crystalline invariants govern the (fractional) quantized corner charges both of isolated material structures and of heterostructures without gapless interface modes. We also show that the partial real-space invariants are able to detect all time-reversal symmetric topological phases of the recently discovered fragile type.

scholarly journals Symmetry-protected nodal points and nodal lines in magnetic materials

2021 ◽  
Vol 103 (24) ◽  
Author(s):  
Jian Yang ◽  
Chen Fang ◽  
Zheng-Xin Liu
Keyword(s):  
Magnetic Materials ◽  
Nodal Lines ◽  
Nodal Points ◽  
Symmetry Protected

scholarly journals Feynman diagrams and rooted maps

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 149-167 ◽  
Author(s):  
Andrea Prunotto ◽  
Wanda Maria Alberico ◽  
Piotr Czerski
Keyword(s):  
Single Particle ◽  
Feynman Diagram ◽  
Feynman Diagrams ◽  
Topological Properties ◽  
Many Body ◽  
Perturbative Order ◽  
Original Definition ◽  
Many Body Systems ◽  
Definition Of ◽  
Particle Propagator

Abstract The rooted maps theory, a branch of the theory of homology, is shown to be a powerful tool for investigating the topological properties of Feynman diagrams, related to the single particle propagator in the quantum many-body systems. The numerical correspondence between the number of this class of Feynman diagrams as a function of perturbative order and the number of rooted maps as a function of the number of edges is studied. A graphical procedure to associate Feynman diagrams and rooted maps is then stated. Finally, starting from rooted maps principles, an original definition of the genus of a Feynman diagram, which totally differs from the usual one, is given.

Transport through several four-quantum-dot topological structures

2021 ◽  
pp. 2150393
Author(s):  
Qingshuang Zhi ◽  
Kongfa Chen ◽  
Zelong He
Keyword(s):  
Quantum Dot ◽  
Coupling Strength ◽  
Bound States ◽  
Resonance Peak ◽  
Coulomb Interactions ◽  
Many Body ◽  
Body Effect ◽  
Topological Structures ◽  
Resonance Band ◽  
Interdot Coupling

In this paper, several four-quantum-dot topological structures are designed. The influence of the interdot coupling strength and intradot Coulomb interactions on the conductance is discussed. The location of the anti-resonance band can be manipulated by tuning the interdot coupling strength, which suggests a physical scheme of an effective quantum switch. The Fano anti-resonance peak may evolve into a resonance peak. For the particular value of the interdot coupling strength, two Fano anti-resonances collapse and bound states in the continuum are formed. Moreover, many-body effect makes the number of anti-resonance bands increase. This study provides a theoretical basis for the design of quantum computing devices.

Many-Body Effect and Device Performance Limit of Monolayer InSe

2018 ◽  
Vol 10 (27) ◽  
pp. 23344-23352 ◽  
Author(s):  
Yangyang Wang ◽  
Ruixiang Fei ◽  
Ruge Quhe ◽  
Jingzhen Li ◽  
Han Zhang ◽  
...  
Keyword(s):  
Device Performance ◽  
Many Body ◽  
Body Effect ◽  
Performance Limit
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