Spin-polarized quantum well states onBi2−xFexSe3

Spin-Polarized Quantum Well States on Bi2-xFexSe3

Passage from spin-polarized surface states to unpolarized quantum well states in topologically nontrivial Sb films.

Topological materials have unusual surface spin properties including a net surface spin current protected by the bulk symmetry properties. When such materials are reduced to thin films, their gapless spin-polarized surface states must connect, by analytic continuation, to bulk-derived quantum-well states, which are spin-unpolarized in centrosymmetric systems. The nature of this passage in a mod...

Collective excitations in an asymmetrically spin-polarized quantum well

We present a phenomenological picture for the many-body excitations of a two-dimensional electron gas in a quantum well spin polarized by a dc magnetic field at an angle u with the axis of the well. In the framework of the Landau theory of charged Fermi liquids, we determine the frequencies of collective modes by solving a transport equation for quasiparticles in the local electromagnetic field...

Spin-flip and spin-wave excitations in arbitrarily polarized quantum Hall states

We study spin-flip and spin-wave excitations for arbitrarily polarized quantum Hall states by employing a fermionic Chern-Simons gauge theory in the low Zeeman energy limit. We show that the spin-flip correlation functions do not get renormalized by the fluctuations of Chern-Simons gauge field. As a consequence, the excitations for a given integer quantum Hall state are identical to fractional ...

Half-polarized quantum hall states.

We report a theoretical analysis of the half-polarized quantum Hall states observed in a recent experiment. Our numerical results indicate that the ground state energy of the quantum Hall nu = 2 / 3 and nu = 2 / 5 states versus spin polarization has a downward cusp at half the maximal spin polarization. We map the two-component fermion system onto a system of excitons and describe the ground st...