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Spin Density Matrix of Spin-3/2 Hole Systems

R. Winkler
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Abstract

For hole systems with an effective spin j=3/2, we present an invariant decomposition of the spin density matrix that can be interpreted as a multipole expansion. The charge density corresponds to the monopole moment and the spin polarization due to a magnetic field corresponds to a dipole moment while heavy hole-light hole splitting can be interpreted as a quadrupole moment. For quasi two-dimensional hole systems in the presence of an in-plane magnetic field B the spin polarization is a higher-order effect that is typically much smaller than one even if the minority spin subband is completely depopulated. On the other hand, the field B can induce a substantial octupole moment which is a unique feature of j=3/2 hole systems.

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R. Winkler. 2004-02-13. Spin Density Matrix of Spin-3/2 Hole Systems. https://doi.org/10.1103/physrevb.70.125301

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