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We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions. The conventional way to apply the rotating wave approximation in a driven high-spin system is to assume the dynamics being restricted in the reduced Hilbert space. However, when the driving strength is relatively strong or the driving is off resonant, the leakage from the target resonance subspace cannot be neglected for a multi-level quantum system. We propose the correct formalism to apply the rotating wave approximation in the full Hilbert space by taking this leakage into account. By estimating the operator fidelity of the time propagator, our formalism applied in the full Hilbert space unambiguously manifests great advantages over the conventional method applied in the reduced Hilbert space.

We introduce a generalized Rashba coupling approximation to analytically solve confined two-dimensional electron systems with both the Rashba and Dresselhaus spin–orbit couplings in an external magnetic field. A solvable Hamiltonian is obtained by performing a simple change of basis, which has the same form as that with only Rashba coupling. Each Landau state becomes a new displaced-Fock state instead of the original Harmonic oscillator Fock state. Analytical energies are consistent with the numerical ones in a wide range of coupling strength even for a strong Zeeman splitting, exhibiting the validity of the analytical approximation. By using the eigenstates, spin polarization correctly displays a jump at the energy-level crossing point, where the corresponding spin conductance exhibits a pronounced resonant peak. As the component of the Dresselhaus coupling increases, the resonant point shifts to a smaller value of the magnetic field. In contrast to pure Rashba couplings, we find that the Dresselhaus coupling and Zeeman splittings tend to suppress the resonant spin Hall effect. Our method provides an easy-to-implement analytical treatment to two-dimensional electron gas systems with both types of spin–orbit couplings by applying a magnetic field.

The process of development and calibration for the first Moon-based extreme ultraviolet (EUV) camera to observe Earth's plasmasphere is introduced and the design, test and calibration results are presented. The EUV camera is composed of a multilayer film mirror, a thin film filter, a photon-counting imaging detector, a mechanism that can adjust the direction in two dimensions, a protective cover, an electronic unit and a thermal control unit. The center wavelength of the EUV camera is 30.2 nm with a bandwidth of 4.6 nm. The field of view is 14.7 degrees with an angular resolution of 0.08 degrees, and the sensitivity of the camera is 0.11 count s(-1) Rayleigh(-1). The geometric calibration, the absolute photometric calibration and the relative photometric calibration are carried out under different temperatures before launch to obtain a matrix that can correct geometric distortion and a matrix for relative photometric correction, which are used for in-orbit correction of the images to ensure their accuracy.

In connection with Bitter–Dubbers experiment, an exact solution for the quantum dynamics of neutrons in magnetic field which is harmonically inhomogeneous (helical) and changes harmonically with time is obtained by invoking a time-dependent transformation with spin–space coupling. It predicts that a beam of neutrons with monotonous momentum will be split into two beams by the magnetic field. As its limiting case, the Berry's geometric phase in moving reference frame appears while the field is very strong.

A field emission measurement profiler, which not only can measure the field emission of the entire film as well as its local points but also can present a two-dimensional map of the current density distribution, is developed. This apparatus is operated under an ultrahigh vacuum condition to measure the field emission distribution of amorphous carbon (a-C) films deposited by a RF magnetron sputtering system. The results show that the film surface consists of strong and weak emission sites. We also obtain the field emission maps of micrometer order from strong and weak emission sites; these can help us understand the mechanism of field emission for improving the procedure for growing films.