All Questions
Tagged with topological-insulators quantum-hall-effect
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The quantum hall effect and Hofstadter's butterfly spectrum
What is the connection between the quantum Hall effect and the Hofstadter's butterfly spectrum? I mean, can I understand something about the quantum Hall effect in the Hofstadter's butterfly spectrum?
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Is there any heat loss in chiral edge channels of topological insulators?
If we are working with nontrivial topological insulator with broken time reversal symmetry then we can expect that we have some chiral edge states. Chiral states have the property that the current can ...
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How can the localization property of the edge mode in topological insulator/quantum hall system be manifested through the effective action?
To be more specific, we can write down the Chern-Simons term from coupling the system to EM to describe the 2d quantum hall system and its derivative respect to the EM field gives the current. How can ...
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What's the relation between quanutm hall effect and topological insulator state?
In a recent PRX paper(https://journals.aps.org/prx/abstract/10.1103/PhysRevX.10.011050), I see that in 45nm and 50nm-thick Cd3As2 films, they find quantum hall effect and say that this is because of ...
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How to calculate $\sigma_{xx}$ in lattice model?
It is known that one can find the Hall conductivity $\sigma_{xy}$ from a lattice model (in a magnetic field, say) using the TKNN formula (PRL 49 405-408 (1982)), i.e. by summing the Chern numbers for ...
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Wiedemann-Franz law generalized to quantum Hall effects in electronic systems
Wiedemann-Franz law states a relation in a conductor between the thermal and electric conductivities by their ratio as $\kappa/\sigma=LT$ where $T$ is the temperature and $L$ is the Lorenz number ...
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Why one can observe Quantum Hall Effect in 3D Topological Insulators in an external magnetic field when TRS is broken?
In magnetotransport experiments scientists have observed the Quantum Hall effect in 3D topolgical insulators. Using a standard hall-bar geaometry in an external magnetic field they see plateaus in the ...
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What makes a topological insulator topological?
I understand that a topological insulator is one with an insulating bulk and conducting surface but I don't understand why or how the topological part comes into it. All of the resources I've found ...
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Is the quantum Hall state a topological insulating state?
I am confused about the quantum Hall state and topological insulating states.
Following are the points (according to my naive understanding of this field) which confuse me:
Topological insulator has ...
- 1,335
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Source Berry Curvature Chern Insulator
Why is there non-zero hall conductance for a Chern insulator?
From section 2.3 of Bernevig's book 'Topological insulators and topological superconductors' I learned one can view degeneracies are ...
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Visualizing k-space tori in 3D
In many introductions to topological insulators (in the exposition of Haldane’s model, for example), we represent the parameter space, a torus, on a plane with axes running from $0$ to $2\pi$.
In an ...
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How does Laughlin argument for hierarchical fractional quantum Hall effect work?
For 1 level and 1 layer $1/q$ FQHE let's say $q=5$ we have the following argument for Laughlin gauge principle. It says that if we adiabatically increase the flux from $0$ to $q\phi_0$ of a corbino ...
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What are the implications that the Hamiltonian of a material lacks time reversal symmetry?
When reading about topological insulators and the quantum Hall effect, I've read that some Hamiltonians of the crystal structure representing the "materials" lack time reversal symmetry. My question ...
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Questions about Berry Phase
I'm learning about the Berry Phase from the original paper, and from the TIFR Infosys Lectures The Quantum Hall Effect by David Tong (2016).
I have some questions regarding the original derivation of ...
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Physical meaning of topological invariant
What does it mean in terms of band structure when we say that any topological invariant of some system is non-zero? For example what does it mean when we say that Chern number=1 in case of IQHE?
Does ...
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