The magnetisation of heavy holes in III-V semiconductor quantum wells with Rashba spin-orbit coupling （SOC） in an external perpendicular magnetic field is studied theoretically. We concentrate on the effects on the magnetisation induced by the system boundary, the l^ashba SOC and the temperature. It is found that the sawtooth-like de Haas- van Alphen （dHvA） oscillations of the magnetisation will change dramatically in the presence of such three factors. Especially, the effects of the edge states and Rashba SOC on the magnetisation are more evident when the magnetic field is smaller. The oscillation center will shift when the boundary effect is considered and the Rashba SOC will bring beating patterns to the dHvA oscillations. These effects on the dHvA oscillations are preferably observed at low temperatures. With increasing temperature, the dHvA oscillations turn to be blurred and eventually disappear.
This paper theoretically investigates the orbital magnetization of electron-doped （n-type） semiconductor het-erostructures and of hole-doped （p-type） bulk semiconductors, which are respectively described by a two-dimensional electron/hole Hamiltonian with both the included Rashba spin-orbit coupling and Zeeman splitting terms. It is the Zeeman splitting, rather than the Rashba spin-orbit coupling, that destroys the time-reversal symmetry of the semiconductor systems and results in nontrivial orbital magnetization. The results show that the magnitude of the orbital magnetization per hole and the Hall conductance in the p-type bulk semiconductors are about 10^-2-10^-1 effective Bohr magneton and 10^-1-1 e^2/h, respectively. However, the orbital magnetization per electron and the Hall conductance in the n-type semiconductor heterostructures are too small to be easily observed in experiment.
By using the linear combination of bulk band （LCBB） method incorporated with the top of the barrier splitting （TBS） model, we present a comprehensive study on the quantum confinement effects and the source-to-drain tunneling in the ultra-scaled double-gate （DG） metal-oxide semiconductor field-effect transistors （MOSFETs）. A critical body thickness value of 5 nm is found, below which severe valley splittings among different X valleys for the occupied charge density and the current contributions occur in ultra-thin silicon body structures. It is also found that the tunneling current could be nearly 100% with an ultra-scaled channel length. Different from the previous simulation results, it is found that the source-to-drain tunneling could be effectively suppressed in the ultra-thin body thickness （2.0 nm and below） by the quantum confinement and the tunneling could be suppressed down to below 5% when the channel length approaches 16 nm regardless of the body thickness.
The orbital magnetization of the electron gas on a two-dimensional kagome' lattice under a perpendicular magnetic field is theoretically investigated.The interplay between the lattice geometry and magnetic field induces nontrivial k-space Chern invariant in the magnetic Brillouin zone,which turns to result in profound effects on the magnetization properties.We show that the Berry-phase term in the magnetization gives a paramagnetic contribution,while the conventional term brought about by the magnetic response of the magnetic Bloch bands produces a diamagnetic contribution.As a result,the superposition of these two components gives rise to a delicate oscillatory structure in the magnetization curve when varying the electron filling factor.The relationship between this oscillatory behavior and the Hofstadter energy spectrum is revealed by selectively discussing the magnetization and its two components at the commensurate fluxes of f = 1/4,1/3,and 1/6,respectively.In particular,we reveal as a typical example the fractal structure in the magnetic oscillations by tuning the commensurate flux around f = 1/4.The finite-temperature effect on the magnetization is also discussed.
The de Haas van Alphen （dHvA） oscillations of electronic magnetization m a monotayer grapnene with structuteinduced spin orbit interaction （SOI） are studied. The results show that the dHvA oscillating centre in this system deviates from the well known （zero） value in a conventional two-dimensional electron gas. The inclusion of S0I will change the well-defined sawtooth pattern of magnetic quantum oscillations and result in a beating pattern. In addition, the SOI effects ola Hall conductance and magnetic susceptibility are also discussed.
