What is the relationship between quantum Hall effect and quantum spin Hall?

Quantum spin Hall effect is a spin version of quantum Hall effect. A quantum spin Hall system possesses a pair of helical edge states, in which an electric current can induce a transverse spin current or a spin accumulation near the system boundary. It is also called two-dimensional topological insulator.

What causes spin Hall effect?

The spin Hall effect is a transport phenomenon consisting of the appearance of spin accumulation on the lateral surfaces of a sample carrying electric current. The opposing surface boundaries will have spins of opposite sign.

How is spin Hall effect measured?

Both P and λsf are obtained by measuring the spin transresistance, ΔR = ΔV/I, as a function of LFM, where ΔV is the difference in the output voltage between parallel and antiparallel magnetization configurations of the FM electrodes at zero magnetic field13,18,19,20,21,22.

What is spin accumulation?

Spin accumulation is a crucial but imprecise concept in spintronics. In metal-based spintronics it is characterized in terms of semiclassical distribution functions. In semiconductors with a strong spin-orbit coupling the spin accumulation is interpreted as a superposition of coherent eigenstates.

What is the difference between Hall effect and quantum Hall effect?

Summary – Hall Effect vs Quantum Hall Effect The quantum Hall effect is derived from the classical Hall effect. The key difference between Hall effect and quantum Hall effect is that the Hall effect mainly occurs on semiconductors, whereas the quantum Hall effect takes place mainly in metals.

What is Haldane model?

The Haldane model on a honeycomb lattice is a paradigmatic example of a Hamiltonian featuring topologically distinct phases of matter1. It describes a mechanism through which a quantum Hall effect can appear as an intrinsic property of a band structure, rather than being caused by an external magnetic field2.

What is the spin Seebeck effect?

The spin Seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters.

What is spin mixing conductance?

The effective spin-mixing conductance (G↑↓eff) of a heavy-metal–ferromagnet (HM-FM) interface characterizes the efficiency of the interfacial spin transport. Accurately determining G↑↓eff is critical to the quantitative understanding of measurements of direct and inverse spin Hall effects.

What is quantum Hall ferromagnetism?

Quantum Hall Ferromagnetism in Graphene Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-like low-energy excitations.

What is quantum Hall effect used for?

Moreover, the value of the quantized resistance is accurate even when materials contain impurities, which would otherwise change the resistance. Because of this, the quantum Hall effect is used to confirm the accuracy of the ohm, the unit of electrical resistance.

What is Chern insulator?

A Chern insulator is 2-dimensional insulator with broken time-reversal symmetry. (If you have for example a 2-dimensional insulator with time-reversal symmetry it can exhibit a Quantum Spin Hall phase). The topological invariant of such a system is called the Chern number and this gives the number of edge states.