Effective particle–hole symmetry breaking, quasi-bond state engineering and optical absorption in graphene based gated dot–ring nanostructures

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 51845-51855
Author(s):  
Leonardo Villegas-Lelovsky ◽  
Gilmar E. Marques ◽  
Fanyao Qu ◽  
Victor Lopez-Richard
Keyword(s):  
Optical Absorption ◽  
Quantum Dot ◽  
Symmetry Breaking ◽  
Graphene Sheet ◽  
Bound States ◽  
Bond State ◽  
Effective Particle ◽  
Ring Structures ◽  
Relativistic Bound States

We have studied the nature- and character- switching of relativistic bound states in quantum dot–ring structures produced by a set of circular concentric metallic gates on a graphene sheet placed over a substrate.

scholarly journals Topological isoconductance signatures in Majorana nanowires

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. S. Ricco ◽  
J. E. Sanches ◽  
Y. Marques ◽  
M. de Souza ◽  
M. S. Figueira ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Transport Properties ◽  
Spin Polarization ◽  
Bound States ◽  
Spin Asymmetry ◽  
Experimental Protocol ◽  
Zero Bias ◽  
Topological Superconductor ◽  
Hybrid Device ◽  
Majorana Bound States

AbstractWe consider transport properties of a hybrid device composed by a quantum dot placed between normal and superconducting reservoirs, and coupled to a Majorana nanowire: a topological superconducting segment hosting Majorana bound states (MBSs) at the opposite ends. It is demonstrated that if highly nonlocal and nonoverlapping MBSs are formed in the system, the zero-bias Andreev conductance through the dot exhibits characteristic isoconductance profiles with the shape depending on the spin asymmetry of the coupling between the dot and the topological superconductor. Otherwise, for overlapping MBSs with less degree of nonlocality, the conductance is insensitive to the spin polarization and the isoconductance signatures disappear. This allows to propose an alternative experimental protocol for probing the nonlocality of the MBSs in Majorana nanowires.

Influence of Ring Structures on Optical Absorption of Trivalent Ytterbium in Yb-Doped Silica Fiber

2021 ◽  
pp. 118370
Author(s):  
Shihao Sun ◽  
Baonan Jia ◽  
Lihong Han ◽  
Gang Liu ◽  
Cong Gao ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Silica Fiber ◽  
Ring Structures

scholarly journals On relativistic entanglement and localization of particles and on their comparison with the nonrelativistic theory

2014 ◽  
Vol 29 (29) ◽  
pp. 1450163 ◽  
Author(s):  
Horace W. Crater ◽  
Luca Lusanna
Keyword(s):  
Bound States ◽  
Clock Synchronization ◽  
Center Of Mass ◽  
Particle Beams ◽  
Open Problems ◽  
Inertial Frames ◽  
Classical Trajectories ◽  
Particle Localization ◽  
Relativistic Bound States ◽  
Classical And Quantum Mechanics

We make a critical comparison of relativistic and nonrelativistic classical and quantum mechanics of particles in inertial frames as well of the open problems in particle localization at both levels. The solution of the problems of the relativistic center-of-mass, of the clock synchronization convention needed to define relativistic 3-spaces and of the elimination of the relative times in the relativistic bound states leads to a description with a decoupled nonlocal (nonmeasurable) relativistic center-of-mass and with only relative variables for the particles (single particle subsystems do not exist). We analyze the implications for entanglement of this relativistic spatial nonseparability not existing in nonrelativistic entanglement. Then, we try to reconcile the two visions showing that also at the nonrelativistic level in real experiments only relative variables are measured with their directions determined by the effective mean classical trajectories of particle beams present in the experiment. The existing results about the nonrelativistic and relativistic localization of particles and atoms support the view that detectors only identify effective particles following this type of trajectories: these objects are the phenomenological emergent aspect of the notion of particle defined by means of the Fock spaces of quantum field theory.

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.

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