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We compared the photoluminescence (PL) properties of AlInAsSb digital alloy samples with different periods grown on GaSb (001) substrates by molecular beam epitaxy. Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states. There are two different mechanisms for the origin of the PL intensity quenching for the AlInAsSb digital alloy. The high-temperature activation energy E 1 is positively correlated with the interface thickness, whereas the low-temperature activation energy E 2 is negatively correlated with the interface thickness. A quantitative high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) study shows that the interface quality improves as the interface thickness increases. Our results confirm that E 1 comes from carrier trapping at a state in the InSb interface layer, while E 2 originates from the exciton binding energy due to the roughness of the AlAs interface layer.

The magnetic states of the strongly correlated system plutonium dioxide (PuO2) are studied based on the density functional theory (DFT) plus Hubbard U (DFT+U) method with spin–orbit coupling (SOC) included. A series of typical magnetic structures including the multiple-k types are simulated and compared in the aspect of atomic structure and total energy. We test LDA, PBE, and SCAN exchange–correlation functionals on PuO2 and a longitudinal 3k antiferromagnetic (AFM) ground state is theoretically determined. This magnetic structure has been identified to be the most stable one by the former computational work using the hybrid functional. Our DFT+U + SOC calculations for the longitudinal 3k AFM ground state suggest a direct gap which is in good agreement with the experimental value. In addition, a genetic algorithm is employed and proved to be effective in predicting magnetic ground state of PuO2. Finally, a comparison between the results of two extensively used DFT+U approaches to this system is made.

When there is a certain amount of field inhomogeneity, the biased ferrimagnetic crystal can exhibit the higher-order magnetostatic (HMS) mode in addition to the uniform-precession Kittel mode. In cavity magnonics, we show the nonlinearity and heating-induced frequency shifts of the Kittel mode and HMS mode in a yttrium–iron–garnet (YIG) sphere. When the Kittel mode is driven to generate a certain number of excitations, the temperature of the whole YIG sample rises and the HMS mode can display an induced frequency shift, and vice versa. This cross effect provides a new method to study the magnetization dynamics and paves a way for novel cavity magnonic devices by including the heating effect as an operational degree of freedom.

By optimizing the V/III beam-equivalent pressure ratio, a high-quality InAs/GaSb type-II superlattice material for the long-wavelength infrared (LWIR) range is achieved by molecular beam epitaxy (MBE). High-resolution x-ray diffraction (HRXRD), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectrometer are used to characterize the material growth quality. The results show that the full width at half maximum (FWHM) of the superlattice zero-order diffraction peak, the mismatching of the superlattice zero-order diffraction peak between the substrate diffraction peaks, and the surface roughness get the best results when the beam-equivalent pressure (BEP) ratio reaches the optimal value, which are 28 arcsec, 13 arcsec, and 1.63 Å, respectively. The intensity of the zero-order diffraction peak is strongest at the optimal value. The relative spectral response of the LWIR detector shows that it exhibits a 100% cut-off wavelength of 12.6 μm at 77 K. High-quality epitaxial materials have laid a good foundation for preparing high-performance LWIR detector.

The 74Se is one of 35 p-nuclei, and 82Se is a r-process only nucleus, and their (n, γ) cross sections are vital input parameters for nuclear astrophysics reaction network calculations. The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured. Prompt γ-rays originating from neutron-induced capture events were detected by four C6D6 liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source (CSNS). The pulse height weighting technique (PHWT) was used to analyze the data in the 1 eV to 100 keV region. The deduced neutron capture cross section was compared with ENDF/B-VIII.0, JEFF-3.2, and JENDL-4.0, and some differences were found. Resonance parameters were extracted by the R-matrix code SAMMY in the 1 eV–1 keV region. All the cross sections of natSe and resonance parameters are given in the datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.

Using an effective field theory with correlations, magnetic properties of an octahedral chain described by a mixed spin Ising model are investigated. Unique phenomena such as multiple hysteresis loops, saturation magnetization, and reverse flip of the magnetization plateaus occur when certain typical parameters are applied. These results may be helpful to further investigate the magnetic properties of one-dimensional systems and could potentially be utilized in the design of spin devices.

The neutron capture cross section of 232Th was measured at the neutron time-of-flight facility Back-n of China Spallation Neutron Source (CSNS) for the first time. The measurement was performed with 4 hydrogen-free deuterated benzene C6D6 liquid scintillation detectors, in the ES#2 experiment station on the beam line, at a distance of about 76 m from the neutron-production assembly. The total energy detection principle in combination with the pulse height weighting technique (PHWT) was applied to analyze the measured data. Results of the 232Th (n, γ) reaction cross section in the unresolved resonance region from 4 keV to 100 keV were obtained, which shows a good agreement with the existing experimental data from EXFOR, as well as with the evaluated data from the ENDF/B-VIII.0 and CENDL-3.1. In addition, the excitation function of 232Th (n, γ)233Th reaction in the unresolved resonance region was theoretically calculated by using the code TALYS-1.95. By fitting the experimental cross section and theoretical data, the average parameters in the unresolved resonance region were extracted. The datasets are openly available at http://dx.doi.org/10.11922/sciencedb.j00113.00015.

The etching and passivation processes of very long wavelength infrared (VLWIR) detector based on the InAs/GaSb/AlSb type-II superlattice have been studied. By studying the effect of each component in the citric acid solution (citric acid, phosphoric acid, hydrogen peroxide, deionized water), the best solution ratio is obtained. After comparing different passivation materials such as sulfide + SiO2, Al2O3, Si3N4 and SU8, it is found that SU8 passivation can reduce the dark current of the device to a greater degree. Combining this wet etching and SU8 passivation, the R 0 A of VLWIR detector with a mesa diameter of 500 μm is about 3.6 Ω⋅cm2 at 77 K.

Silver indium cadmium (Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants, and it is continuously consumed in a high neutron flux environment. The mass ratio of 107Ag in the Ag–In–Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the 107Ag is required. Meanwhile, 107Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with 107Ag are very important both in nuclear energy and nuclear astrophysics. The (n, γ) cross section of 107Ag has been measured in the energy range of 1–60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of 107Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.

A high-neutron yield platform imploded by a thin shell target is generally built to probe nuclear science problems, and it has the advantages of high neutron yield, ultrashort fusion time, micro fusion zone, isotropic and monoenergetic neutron. Some analytical models have been proposed to interpret exploding-pusher target implosion driven by a long wavelength laser, whereas they are imperfect for a 0.35 μm laser implosion experiment. When using the 0.35 μm laser, the shell is ablated and accelerated to high implosion velocity governed by Newton’s law, ablation acceleration and quasi-adiabatic compression models are suitable to explain the implosion of a laser direct-drive thin shell target. The new analytical model scales bang time, ion temperature and neutron yield for large variations in laser power, target radius, shell thickness, and fuel pressure. The predicted results of the analytical model are in agreement with experimental data on the Shenguang-III prototype laser facility, 100 kJ laser facility, Omega, and NIF, it demonstrates that the analytical model benefits the understanding of experiment performance and optimizing the target design of high neutron yield implosion.

We theoretically study the transport properties in the T-shaped double-quantum-dot structure, by considering the dot in the main channel to be coupled to the Majorana bound state (MBS) at one end of the topological superconducting nanowire. It is found that the side-coupled dot governs the effect of the MBS on the transport behavior. When its level is consistent with the energy zero point, the MBS contributes little to the conductance spectrum. Otherwise, the linear conductance exhibits notable changes according to the inter-MBS coupling manners. In the absence of inter-MBS coupling, the linear conductance value keeps equal to e 2/2h when the level of the side-coupled dot departs from the energy zero point. However, the linear conductance is always analogous to the MBS-absent case once the inter-MBS coupling comes into play. These findings provide new information about the leakage effect of MBSs in quantum-dot structures.

With the semiclassical ensemble model, we explore the relative phase-dependent nonsequential double ionization (NSDI) of Mg by counter-rotating two-color circularly polarized (TCCP) laser pulses. The yield of Mg2+ sensitively depends on the relative phase Δφ and the intensity of TCCP laser fields. At Δφ = 1.5π, the yield of Mg2+ exhibits a pronounced peak in the 0.05 PW/cm2 laser field. This behavior results from the increase of the initial transverse velocity compensating for the drift velocity with the decreasing angle by analyzing the angular distributions of the electron pairs in four relative phases. By changing the relative phases, we find that the recollision excitation with subsequent ionization and the recollision-impact ionization mechanisms can be controlled with TCCP laser fields.

We present a theoretical investigation of the multiphoton resonance dynamics in the high-order-harmonic generation (HHG) process driven by a strong driving continuous wave (CW) field along with a weak control harmonic field. The Floquet theorem is employed to provide a nonperturbative and exact treatment of the interaction between a quantum system and the combined laser field. Multiple multiphoton-transition paths for the harmonic emission are coherently summed. The phase information about paths can be extracted via the Fourier transform analysis of the harmonic signals which oscillate as a function of the relative phase between driving and control fields. Phase jumps are observed when sweeping across the resonance by varying the frequency or intensity of the driving field. The phase variation as a function of driving frequency at a fixed intensity and as a function of the intensity at a fixed driving frequency allows us to determine the intensity dependence of the transition energy of quantum systems.

Polar dielectrics are important optical materials enabling the subwavelength manipulation of light in infrared due to their capability to excite phonon polaritons. In practice, it is highly desired to actively modify these hyperbolic phonon polaritons (HPPs) to optimize or tune the response of the device. In this work, we investigate the plasmonic material, a monolayer graphene, and study its hybrid structure with three kinds of hyperbolic thin films grown on SiO2 substrate. The inter-mode hybridization and their tunability have been thoroughly clarified from both the band dispersions and the mode patterns numerically calculated through a transfer matrix method. Our results show that these hybrid multilayer structures are of strong potentials for applications in plasmonic waveguides, modulators and detectors in infrared.

A one-dimensional hybrid model was developed to study the electrical asymmetry effect (EAE) caused by the fourth-order harmonic in a dual-frequency capacitively coupled Ar plasma. The self-bias voltage caused by the fourth-order frequency changes periodically with the phase angle, and the cycle of self-bias with the phase angle is π/2, which is half of that in the second-order case. The influence of the phase angle between the fundamental and its fourth-order frequency on the ion density profiles and the ion energy distributions (IEDs) were studied. Both the ion density profile and the IEDs can be controlled by the phase angle, which provides a convenient way to adjust the sheath characters without changing the main discharge parameters.

The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L12 structure Al3Tm and Al3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al3Tm and Al3Lu keep their dynamical stabilities in L12 structure up to 100 GPa. The elastic properties and Debye temperatures for Al3Tm and Al3Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the three-dimensional (3D) curved surface of Young's modulus. The calculated results show that Al3Tm and Al3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al3Tm and Al3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications.

From first principle calculations, we demonstrate that LiXS2 (X = Ga, In) compounds have potential applications as cathode materials for Li ion batteries. It is shown that Li can be extracted from the LiXS2 lattice with relatively small volume change and the XS4 tetrahedron structure framework remains stable upon delithiation. The theoretical capacity and average intercalation potential of the LiGaS2 (LiInS2) cathode are 190.4 (144.2) mAh/g and 3.50 V (3.53 V). The electronic structures of the LiXS2 are insulating with band gaps of 2.88 eV and 1.99 eV for X = Ga and In, respectively. However, Li vacancies, which are formed through delithiation, change the electronic structure substantially from insulating to metallic structure, indicating that the electrical conductivities of the LiXS2 compounds should be good during cycling. Li ion migration energy barriers are also calculated, and the results show that Li ion diffusions in the LiXS2 compounds can be as good as those in the currently widely used electrode materials.

An implicit electrostatic particle-in-cell/Monte Carlo (PIC/MC) algorithm is developed for the magnetized discharging device simulation. The inductive driving force can be considered. The direct implicit PIC algorithm (DIPIC) and energy conservation scheme are applied together and the grid heating can be eliminated in most cases. A tensor-susceptibility Poisson equation is constructed. Its discrete form is made up by a hybrid scheme in one-dimensional (1D) and two-dimensional (2D) cylindrical systems. A semi-coarsening multigrid method is used to solve the discrete system. The algorithm is applied to simulate the cylindrical magnetized target fusion (MTF) pre-ionization process and get qualitatively correct results. The potential application of the algorithm is discussed briefly.

We benchmark and analyze the error of energy conservation (EC) scheme in particle-in-cell/Monte Carlo (PIC/MC) algorithms by simulating the radio frequency discharge. The plasma heating behaviors and electron distributing functions obtained by one-dimensional (1D) simulation are analyzed. Both explicit and implicit algorithms are checked. The results showed that the EC scheme can eliminated the self-heating with wide grid spacing in both cases with a small reduction of the accuracies. In typical parameters, the EC implicit scheme has higher precision than EC explicit scheme. Some "numerical cooling" behaviors are observed and analyzed. Some other errors are also analyzed. The analysis showed that the EC implicit scheme can be used to qualitative estimation of some discharge problems with much less computational resource cost without much loss of accuracies.

LaOsSi3 single crystals are synthesized for the first time by an arc melting method. The crystal features a tetragonal BaNiSn3-type structure (space group I4mm) which lacks inversion symmetry along the crystallographic c axis and is isostructural with the intensively studied Rashba-type noncentrosymmetric superconductors LaRhSi3 and LaIrSi3. Unlike LaRhSi3 and LaIrSi3 displaying superconductivity, LaOsSi3 shows only metallic behavior over the measured temperature range of 2 K-300 K. The Sommerfeld coefficient gamma derived from specific heat is 5.76 mJ.mol(-1).K-2, indicating that LaOsSi3 has a weak electronic correlation effect. The absence of superconductivity in LaOsSi3 may lie in the Os 5d bands in the electronic structure. If it is true, it would be useful to provide complementary knowledge in understanding the relation between conduction and the d bands of M in LaMSi3 compounds (M = transition metals).

A two-dimensional (2D) fluid model is presented to study the behavior of silicon plasma mixed with SiH4, N2, and NH3 in a radio-frequency capacitively coupled plasma (CCP) reactor. The plasma-wall interaction (including the deposition) is modeled by using surface reaction coefficients. In the present paper we try to identify, by numerical simulations, the effect of variations of the process parameters on the plasma properties. It is found from our simulations that by increasing the gas pressure and the discharge gap, the electron density profile shape changes continuously from an edge-high to a center-high, thus the thin films become more uniform. Moreover, as the N2/NH3 ratio increases from 6/13 to 10/9, the hydrogen content can be significantly decreased, without decreasing the electron density significantly.

The low laser induced damage threshold of the KH2PO4 crystal seriously restricts the output power of inertial confinement fusion. The micro-waviness on the KH2PO4 surface processed by single point diamond turning has a significant influence on the damage threshold. In this paper, the influence of micro-waviness on the damage threshold of the KH2PO4 crystal and the chief sources introducing the micro-waviness are analysed based on the combination of the Fourier modal theory and the power spectrum density method. Research results indicate that among the sub-wavinesses with different characteristic spatial frequencies there exists the most dangerous frequency which greatly reduces the damage threshold, although it may not occupy the largest proportion in the original surface. The experimental damage threshold is basically consistent with the theoretical calculation. For the processing parameters used, the leading frequency of micro-waviness which causes the damage threshold to decrease is between 350−1 μm−1 and 30−1 μm−1, especially between 90−1 μm−1 and 200−1 μm−1. Based on the classification study of the time frequencies of micro-waviness, we find that the axial vibration of the spindle is the chief source introducing the micro-waviness, nearly all the leading frequencies are related to the practical spindle frequency (about 6.68 Hz, 400 r/min) and a special middle frequency (between 1.029 Hz and 1.143 Hz).

We theoretically study the measurement-induced dephasing caused by back action noise in quantum nondemolition measurements of a superconducting flux qubit which is coupled to a superconducting quantum interference device (SQUID). Our analytical results indicate that information on qubit flows from qubit to detector, while quantum fluctuations which may cause dephasing of the qubit also inject to qubit. Furthermore, the measurement probability is frequency dependent in a short time scale and has a close relationship with the measurement-induced dephasing. When the detuning between driven and bare resonator equals coupling strength, we will access the state of qubit more easily. In other words, we obtain the maximum measurement rate. Finally, we analyzed mixed effect caused by coupling between non-diagonal term and external variable. We found that the initial information of qubit is destroyed due to quantum tunneling between the qubit states., 6 pages, 3 figures