RESUMEN
The recent discovery of superconductivity in infinite-layer nickelates generates tremendous research endeavors, but the ground state of their parent compounds is still under debate. Here, we report experimental evidence for the dominant role of Kondo scattering in the underdoped Nd1-xSrxNiO2 thin films. A resistivity minimum associated with logarithmic temperature dependence in both longitudinal and Hall resistivities are observed in the underdoped Nd1-xSrxNiO2 samples before the superconducting transition. At lower temperatures down to 0.04 K, the resistivities become saturated, following the prediction of the Kondo model. A linear scaling behavior [Formula: see text] between anomalous Hall conductivity [Formula: see text] and conductivity [Formula: see text]is revealed, verifying the dominant Kondo scattering at low temperature. The effect of weak (anti-)localization is found to be secondary. Our experiments can help in clarifying the basic physics in the underdoped Nd1-xSrxNiO2 infinite-layer thin films.
RESUMEN
Correlated states have emerged in low-dimensional systems owing to enhanced Coulomb interactions. Elucidating these states requires atomic-scale characterization and delicate control capabilities. Herein, spectroscopic imaging-scanning tunneling microscopy was employed to investigate the correlated states residing in 1D electrons of the monolayer and bilayer MoSe2 mirror twin boundary (MTB). The Coulomb energies, determined by the wire length, drive the MTB into two types of ground states with distinct respective out-of-phase and in-phase charge orders. The two ground states can be reversibly converted through a metastable zero-energy state with in situ voltage pulses, which tune the electron filling of the MTB via a polaronic process, substantiated by first-principles calculations. Our Hubbard model calculation with an exact diagonalization method reveals the ground states as correlated insulators from an on-site U-originated Coulomb interaction, dubbed the Hubbard-type Coulomb blockade effect. Our study lays a foundation for understanding and tailoring correlated physics in complex systems.
RESUMEN
Transparent material has been widely used in product design and has seen a large increase in its use. In this paper, a kind of aesthetically decorative 5 GHz Wi-Fi dielectric resonator antenna (DRA) of aluminum oxynitride (AlON) transparent ceramic has been designed. High-quality-factor AlON transparent dielectric ceramics were fabricated by presintering at 1780 °C and further cold isostatic pressing (CIP) under a 200 MPa argon atmosphere. For a 9.0 mm thick specimen, the in-line light transmittance reached 83%. Optimum dielectric constant (εr = 9.32), quality factor (Qf = 47â¯960) and temperature coefficient (TCF = -51.7 ppm/°C) was achieved in the AlON transparent ceramic by cold isostatic pressing. As a result, the proposed aesthetically decorative DRA can achieve an impedance bandwidth of 32% (4.48-6.19 GHz), a high radiation efficiency of 85%, and a low cross-polarization discrimination (XPD) of -30 dB. To achieve a broad bandwidth, the proposed antenna was excited in its dominant TE111x mode and higher-order TE113x mode. The proposed antenna is thus an excellent candidate for an indoor decoration Wi-Fi antenna.
RESUMEN
Digital micro-mirror device (DMD) can be controlled to form Hadamard encoding masks flexibly and efficiently. A kind of Hadamard transform spectral imager of adaptive spectral resolution based on DMD is proposed. The structure and the working principle of the instrument are described and the implementation method of adaptive spectral resolution is analyzed. It can adjust the spectral resolution according to the target and the observational requirements, and a reasonable compromise can be reached between the spectral accuracy and the computation of data. It not only meets the requirements of the target classification and recognition, but also improves the speed of data transmission and processing.
RESUMEN
A novel type of DMD-based Hadamard transform spectral imager is introduced. Taking the 7-order S-matrix as an example for discussion, the present paper develops an improved design of Hadamard encoding mask, which makes the dispersed spectrum of all pixels to be encoded by seven elements strictly. A correcting method for the recovered spectral images is proposed, and eventually 6 high-quality spectral images are obtained when Hadamard transform spectral imager operates based on 7-order S-matrix. Similarly, if the spectral imager operates based on n-order S-matrix, n--1 spectral images can be obtained. The experimental results show that the improved design and the correction method are feasible and effective.