Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>With the development of research on integrated photonic quantum information processing, the integration level of the integrated quantum photonic circuits has been increasing continuously, which makes the calibration of the phase shifters on the chip increasingly difficult. For the calibration of multiple cascaded phase shifters that is not easy to be decoupled, the resources consumed by conventional brute force methods increase exponentially with the number of phase shifters, making it impossible to calibrate a relatively large number of cascaded phase shifters. In this work, we experimentally validate an efficient method for calibrating cascaded phase shifters that achieves an exponential increase in calibration efficiency compared to the conventional method, thus solving the calibration problem for multiple cascaded phase shifters. Specifically, we have experimentally calibrated an integrated quantum photonic circuit with nine cascaded phase shifters and achieved a high-precision calibration with an average fidelity of 99.26%.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This work built an isobaric steady-state fluid analytical-physical model of the plasma conduction region in the conical target. The hydrodynamic instability in the double-cone ignition scheme [doi:10.1098/rsta.2020.0015] for inertial confinement fusion proposed by J. Zhang is studied with the built model. With this idealized model, the relevant parameters, such as density, temperature, length, etc., of the plasma in the conduction region of the conical target under long-pulse conditions are given. The solution of the proposed analytical model dovetails with the trend of the numerical simulation. The model and results in this paper are beneficial for discussing how to attenuate Rayleigh-Taylor instability (RTI) in inertial confinement fusion processes with conical and spherical targets.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Spin pumping (SP) and inverse spin Hall effect (ISHE) driven by parametrically-excited dipole-exchange spin waves in a yttrium iron garnet film have been systematically investigated. The measured voltage spectrum exhibits a feature of the field-induced transition from parallel pumping to perpendicular pumping because of the inhomogeneous excitation geometry. Thanks to the high precision of the SP-ISHE detection, two sets of fine structures in the voltage spectrum are observed, which can correspond well to two kinds of critical points in the multimode spin-wave spectrum for magnetic films. One is the <jats:italic>q</jats:italic> = 0 point of each higher-order dispersion branch, and the other is the local minimum due to the interplay between the dipolar and exchange interactions. These fine structures on the voltage spectrum confirm the spin pumping by higher-order dipole-exchange spin-wave modes, and are helpful for probing the multimode spin-wave spectrum.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Flexible spin valves were prepared by magnetron sputtering on polyimide substrates. The buffer layer that reduces significantly the effect of the polymer substrate on the spin valve microstructure and magnetoresistive properties was revealed. Bending deformation was applied to the microobjects based on the flexible spin valves in parallel to anisotropy axes. It was revealed that during the bend the magnetoresistance changes due to the joint impact of both the change of the magnetic field projection on the film plane and the change of the magnetic properties of ferromagnetic layers. The obtained dependences have been used in construction of bending sensor, in which the flexible spin valve microstripes were united into the Wheatstone bridge.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This paper studied the low-resistance ohmic contacts on InAlN/GaN with metal-organic chemical vapor deposition (MOCVD) regrowth technique. The 150 nm regrown n<jats:sup>+</jats:sup>-InGaN exhibits a low sheet resistance of 31Ω/□, resulting in an extremely low contact resistance of 0.102Ω·mm between n<jats:sup>+</jats:sup>-InGaN and InAlN/GaN channel. Mask-free regrowth process was also used to significantly improve the sheet resistance of InAlN/GaN with MOCVD regrown ohmic contacts. Then, the diffusion mechanism between n<jats:sup>+</jats:sup>-InGaN and InAlN during regrowth process was investigated with electrical and structural characterization, which could benefit the further process optimization.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>High-entropy alloys (HEAs) and medium-entropy alloys (MEAs), have received much attention for developing nuclear materials because of their excellent irradiation tolerance. Herein, the formation and evolution of radiation-induced defects in Ni–Co–Fe MEA and pure Ni are investigated and compared using molecular dynamics simulation. It is observed that the defect recombination rate of ternary Ni–Co–Fe MEA is higher than that of pure Ni, which is mainly because, in the process of cascade collision, the energy dissipated through atom displacement decreases with increasing the chemical disorder. Consequently, the heat peak phase lasts longer, and the recombination time of the radiation defects (interstitial atoms and vacancies) is likewise longer, with fewer deleterious defects. Moreover, by studying the formation and evolution of dislocation loops in Ni–Co–Fe alloys and Ni, it is found that the stacking fault energy in Ni–Co–Fe decreases as the elemental composition increases, facilitating the formation of ideal stacking fault tetrahedron structures. Hence, these findings shed new light on studying the formation and evolution of radiation-induced defects in MEAs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>High critical current density (&amp;#62;10<jats:sup>6</jats:sup> A/cm<jats:sup>2</jats:sup>) is one of major obstacles to realize the practical application of the current-driven magnetization reversal devices. In this work, we have successfully prepared Pd/CoZr(3.5 nm)/MgO thin films with large perpendicular magnetic anisotropy and demonstrated a way of reducing the critical current density with a low out-of-plane magnetic field in the Pd/CoZr/MgO stack. Under the assistance of an out-of-plane magnetic field, the magnetization can be fully reversed with a current density of about 10<jats:sup>4</jats:sup> A/cm<jats:sup>2</jats:sup>. The magnetization reversal is attributed to the combined effect of the out-of-plane magnetic field and the current-induced spin-orbital torque. It was found that the current-driven magnetization reversal is highly relevant to the temperature owing to the varied spin-orbital torque; and the current-driven magnetization reversal will be more efficient at low temperature range, while the magnetic field is helpful for the magnetization reversal at high temperature range.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We investigate the ionization of an atom with different orbital angular momenta in the high frequency laser field by solving the time-dependent Schrödinger equation. It is found that the ionization stabilization features changed with the relative direction between the angular momentum of the initial state and the vector field of the laser pulse. With the calculation of the transition matrix and the evolution of the time-dependent wavepacket, the ionization mechanism of the atom irradiated by the high frequency is explained. This study can further deepen the understanding of the atomic nonadiabatic ionization progress.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Non-Hermitian dissipation dynamics, capable of turning the conventionally detrimental decoherence effects to useful resources for state engineering, is highly attractive to quantum information processing. In this work, an effective scheme is developed for implementing fast population transfer with a superconducting qutrit via the non-Hermitian shortcut to adiabaticity (STA). We first deal with a Λ-configuration interaction between the qutrit and microwave drivings, in which the dephasing-assisted qubit state inversion requiring an overlarge dephasing rate is constructed non-adiabatically. After introducing a feasible ancillary driving that directly acts upon the qubit states, the target state transfer can be well realized but with an accessible qubit dephasing rate. Moreover, a high fidelity could be numerically obtained in the considered system. The strategy could provide a new route towards the non-Hermitian shortcut operations on superconducting quantum circuits.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>By studying the thermal conductivity, specific heat, elastic modulus, and thermal expansion as a function of temperature for Cd<jats:sub>3</jats:sub>As<jats:sub>2</jats:sub>, we have unveiled a couple of important thermodynamic features of the low-energy phonons strongly interacting with Dirac electrons. The existence of soft optical phonons, as inferred from the extremely low thermal conductivity, is unambiguously confirmed by low-temperature specific heat revealing significant deviation from Debye’s description. The estimated Debye temperature is small in the range of 100 - 200 K and varies significantly depending upon the measurement used in its experimental determination. The thermodynamic Grüneisen ratio γ reveals a remarkable reduction below about 100 K, an energy scale that is highly relevant to the Dirac states, towards negative values below about 10 K that are indicative of lattice instability.</jats:p>