scholarly journals Strain-induced Localization-delocalization Transition on a Lieb Ribbon Lattice

2021 ◽  
Author(s):  
Diego Román-Cortés ◽  
Guillermo Fadic ◽  
Christofer Cid-Lara ◽  
Diego Guzmán-Silva ◽  
Bastián Real ◽  
...  
Keyword(s):  
Transport Properties ◽  
Excellent Agreement ◽  
Compression Ratio ◽  
Mechanical Deformation ◽  
Two Dimensions ◽  
Flat Band ◽  
Transition Systems ◽  
Band Deformation

Abstract Ribbon lattices are kind of transition systems in between one and two dimensions, and their study is crucial to understand the origin of different emerging properties. In this work, we study a Lieb ribbon lattice and the localization-delocalization transition occurring due to a reduction of lattice distances (compression) and the corresponding flat band deformation. We observe how above a critical compression ratio the energy spreads out and propagates freely across the lattice, therefore transforming the system from being a kind of insulator into a conductor. We implement an experiment on a photonic platform and show an excellent agreement with the predicted phenomenology. Our findings suggest and prove experimentally the use of compression or mechanical deformation of lattices to switch the transport properties of a given system.

scholarly journals Strain induced localization to delocalization transition on a Lieb photonic ribbon lattice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diego Román-Cortés ◽  
Guillermo Fadic ◽  
Christofer Cid-Lara ◽  
Diego Guzmán-Silva ◽  
Bastián Real ◽  
...  
Keyword(s):  
Transport Properties ◽  
Excellent Agreement ◽  
Compression Ratio ◽  
Mechanical Deformation ◽  
Two Dimensions ◽  
Flat Band ◽  
Transition Systems ◽  
Band Deformation

AbstractRibbon lattices are kind of transition systems in between one and two dimensions, and their study is crucial to understand the origin of different emerging properties. In this work, we study a Lieb ribbon lattice and the localization–delocalization transition occurring due to a reduction of lattice distances (compression) and the corresponding flat band deformation. We observe how above a critical compression ratio the energy spreads out and propagates freely across the lattice, therefore transforming the system from being a kind of insulator into a conductor. We implement an experiment on a photonic platform and show an excellent agreement with the predicted phenomenology. Our findings suggest and prove experimentally the use of compression or mechanical deformation of lattices to switch the transport properties of a given system.

Two-Step Evolution of the Quasiparticle Band with Doping in the Two-Dimensional t-t′-t″-J Model

1998 ◽  
Vol 12 (29n31) ◽  
pp. 2914-2919
Author(s):  
Chang-De Gong ◽  
Wei-Guo Yin ◽  
P. W. Leung
Keyword(s):  
Theoretical Analysis ◽  
Excellent Agreement ◽  
Exact Diagonalization ◽  
Flat Band ◽  
Two Dimensional ◽  
Doping Dependence ◽  
Flat Region ◽  
Half Filling ◽  
Quasiparticle Band

We study the doping dependence of photoemission spectra for the t-t′-t″-J model by using the exact diagonalization technique and present a consistent theoretical analysis. Both calculations show that upon doping the enhancement of incoherent motion of holes due to the t′ and t″ terms accounts for the formation of the flat region around (π,0) in the quasiparticle dispersion at underdoped and optimally doped region, despite the absence of the flat band at half filling. Our results are in excellent agreement with resent photoemission experiments on Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ [Marshall et al., Phys. Rev. Lett.76, 4841 (1996)] and Sr 2 CuO 2 Cl 2 [Wells et al., Phys. Rev. Lett.74, 964 (1995)].

Enhanced thermoelectric transport properties of n-type InSe due to the emergence of the flat band by Si doping

2019 ◽  
Vol 6 (6) ◽  
pp. 1475-1481 ◽  
Author(s):  
Kyu Hyoung Lee ◽  
Min-Wook Oh ◽  
Hyun-Sik Kim ◽  
Weon Ho Shin ◽  
Kimoon Lee ◽  
...  
Keyword(s):  
Transport Properties ◽  
Figure Of Merit ◽  
Flat Band ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Transport ◽  
Si Doping ◽  
Thermoelectric Transport Properties ◽  
Si Doped

An improved thermoelectric figure of merit (zT) of 0.14 at 795 K was obtained in 7% Si doped InSe due to the emergence of the flat band.

Thermoelectric generators made of FeSi2 and HMS: Fabrication and measurement

1995 ◽  
Vol 10 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Erwin Groβ ◽  
Michael Riffel ◽  
Ulrich Stöhrer
Keyword(s):  
Transport Properties ◽  
Excellent Agreement ◽  
Electrical Contacts ◽  
Peltier Effect ◽  
Thermoelectric Generators ◽  
Cold Side ◽  
Working Temperature ◽  
Measured Efficiency ◽  
Manganese Silicide ◽  
Ultrasonic Soldering

Single couple thermoelectric generators consisting of n-type FeSi2 and p-type higher manganese silicide were developed and characterized. The leg and the bridge materials were prepared by a powder metallurgical method. Using the Peltier effect the transport properties were measured over the whole working temperature range. Electrical contacts suitable for the hot side could be obtained by conventional vacuum soldering and those for the cold side by ultrasonic soldering. The measured efficiency was in excellent agreement with the calculated values derived from the leg and contact properties.

scholarly journals Percolation and Transport Properties in The Mechanically Deformed Composites Filled with Carbon Nanotubes

2020 ◽  
Vol 10 (4) ◽  
pp. 1315 ◽  
Author(s):  
Artyom Plyushch ◽  
Dmitry Lyakhov ◽  
Mantas Šimėnas ◽  
Dzmitry Bychanok ◽  
Jan Macutkevič ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Material ◽  
Aspect Ratio ◽  
Percolation Threshold ◽  
Transport Properties ◽  
High Aspect Ratio ◽  
Hard Core ◽  
Mechanical Deformation ◽  
Mean Values ◽  
Isotropic Composite

The conductivity and percolation concentration of the composite material filled with randomly distributed carbon nanotubes were simulated as a function of the mechanical deformation. Nanotubes were modelled as the hard-core ellipsoids of revolution with high aspect ratio. The evident anisotropy was observed in the percolation threshold and conductivity. The minimal mean values of the percolation of 4.6 vol. % and maximal conductivity of 0.74 S/m were found for the isotropic composite. Being slightly aligned, the composite demonstrates lower percolation concentration and conductivity along the orientation of the nanotubes compared to the perpendicular arrangement.

NORMAL STATE TRANSPORT PROPERTIES OF (Bi0.8Pb0.2-yVy)2Sr2Ca2Cu3O10+δ SUPERCONDUCTING PELLETS

2000 ◽  
Vol 14 (22n23) ◽  
pp. 827-835
Author(s):  
A. K. DHAMI ◽  
S. BASAK ◽  
S. K. GHATAK ◽  
T. K. DEY
Keyword(s):  
Electrical Resistivity ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Excellent Agreement ◽  
Normal State ◽  
Vanadium Content ◽  
State Model ◽  
Three State Model

The electrical resistivity and thermoelectric power of (B i 0.8P b 0.2-yVy)2S r 2C a 2C u 3O10+δ pellets with 0≤y≤0.05 is reported between Tc0 and 300 K. Thermoelectric power values of all samples were found to be positive and increase almost linearly with decrease of temperature down to ~120 K, before falling to zero at Tc0. With increasing vanadium content in (Bi,Pb)-2223 compounds, the magnitude of both the electrical resistivity and thermoelectric power increases. General features, however, remain the same. The results have been discussed on the framework of a "three-state model". Our analysis shows an excellent agreement between the measured electrical resistivity and thermoelectric power data and those calculated using the three-state model.

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