Article
Physics, Applied
Oksana Chubenko, Siddharth Karkare, Dimitre A. Dimitrov, Jai Kwan Bae, Luca Cultrera, Ivan Bazarov, Andrei Afanasev
Summary: The anticorrelation between quantum efficiency (QE) and electron spin polarization (ESP) in p-doped GaAs is studied using a Monte Carlo approach, showing that the behavior can be explained by bulk relaxation mechanisms and the time electrons spend in the material.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
S. Anghel, A. V. Poshakinskiy, K. Schiller, G. Yusa, T. Mano, T. Noda, M. Betz
Summary: This study investigates the correlation between spin diffusion, spin lifetime, and electron density in low-dimensional GaAs semiconductors. It reveals that the variation in the scattering rate with electron density is more important than fulfilling the persistent spin helix condition for achieving the longest spin lifetime. The experiment shows that the longest spin lifetime occurs at the transition from Boltzmann to Fermi-Dirac statistics for electron density.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
H. Hijazi, D. Paget, G. Monier, G. Gregoire, J. Leymarie, E. Gil, F. Cadiz, C. Robert-Goumet, Y. Andre
Summary: Despite the expected difficulties due to high doping levels, it was found that charge and spin transport are achievable in n-type metallic GaAs nanowires, with the potential for long-distance spin transport. This was demonstrated through spatially and spectrally resolved investigations of luminescence intensity and circular polarization under laser excitation.
Article
Materials Science, Multidisciplinary
San-Dong Guo, Xu-Kun Feng, Dong Huang, Shaobo Chen, Guangzhao Wang, Yee Sin Ang
Summary: This study reveals that T-XY monolayers possess persistent spin helix structure, which can be applied in spintronic devices and provide a promising platform for on-off logical functionality.
Article
Materials Science, Multidisciplinary
San-Dong Guo, Xu-Kun Feng, Dong Huang, Shaobo Chen, Guangzhao Wang, Yee Sin Ang
Summary: Persistent spin texture (PST) and persistent spin helix (PSH) are of great importance for improving the performance of spintronic devices. In this study, T-XY monolayers are predicted to possess PST and can be used to achieve on-off logical functionality using an external electric field.
Article
Multidisciplinary Sciences
Peter Millington-Hotze, Santanu Manna, Saimon F. Covre da Silva, Armando Rastelli, Evgeny A. Chekhovich
Summary: The spin diffusion in inhomogeneously polarized many-body systems, such as nuclear spin lattices, is described classically by the spin diffusion concept. In this study, the authors directly observed spin diffusion in a single GaAs/AlGaAs quantum dot through oscillatory spin relaxation dynamics and found that electron spin accelerates nuclear spin relaxation, challenging the previously proposed Knight-field-gradient diffusion barrier concept. The findings have significant implications for understanding nuclear spin diffusion in quantum dots.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Jing Wu, Hui Ming Hao, Yu Liu, Yang Zhang, Xiao Lin Zeng, Shen Bo Zhu, Zhi Chuan Niu, Hai Qiao Ni, Yong Hai Chen
Summary: The anomalous circular photogalvanic effect (ACPGE) is observed in p-GaAs with a thickness of 2 mu m at room temperature. The normalized ACPGE signals show a trend of first increasing and then decreasing with increasing doping concentration. Both extrinsic and intrinsic models are discussed to explain the role of doping impurities in the variation of ACPGE.
Article
Materials Science, Multidisciplinary
P. Sterin, L. Abaspour, J. G. Lonnemann, E. P. Rugeramigabo, J. Huebner, M. Oestreich
Summary: We present a detailed study of the temperature-dependent electron spin relaxation rate in n-type bulk GaAs and observe the longest spin relaxation time slightly below the metal-to-insulator transition at a finite temperature. This phenomenon results from the delicate interplay of hyperfine interaction, variable range hopping, and the Dyakonov-Perel mechanism.
Article
Physics, Multidisciplinary
D. Zhao, Y. B. Zhou, Y. Fu, L. Wang, X. F. Zhou, H. Cheng, J. Li, D. W. Song, S. J. Li, B. L. Kang, L. X. Zheng, L. P. Nie, Z. M. Wu, M. Shan, F. H. Yu, J. J. Ying, S. M. Wang, J. W. Mei, T. Wu, X. H. Chen
Summary: The recent discovery of superconductivity in doped infinite-layer nickelates has sparked interest in studying the similarities and differences with cuprate superconductors. While earlier magnetization measurements showed behavior similar to Curie-Weiss in undoped nickelates, no magnetic ordering was observed by neutron scattering. Nuclear magnetic resonance experiments confirmed a paramagnetic ground state in LaNiO2, with pseudogaplike behavior observed in temperature-dependent Knight shift and nuclear spin-lattice relaxation rate. The results suggest a significant exchange interaction in infinite-layer nickelates, which presents a challenge for theoretical models.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Christian S. Ahart, Kevin M. Rosso, Jochen Blumberger
Summary: This study uses density functional theory to uncover the nature and transport mechanism of holes and excess electrons in hematite. It finds that the transport mechanism is influenced by tetragonal distortion, with holes relaxing from delocalized states to localized polaron states, and excess electrons inducing smaller distortions resulting in delocalization over neighboring units.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Physics, Applied
Chen Qiu, Ruyue Cao, Fei Wang, Hui-Xiong Deng
Summary: This study systematically investigated the intrinsic defect properties in monolayer black phosphorus and black arsenic, revealing P and As vacancies as shallow dominating acceptors leading to p-type conductivity. The results help explain the origin of the p-type conductivity in these materials and enhance the understanding of defect properties in two-dimensional materials.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Bo Wang, Gaoshuai Wei, Jianing Chen, Li Wang
Summary: This study investigates ultrafast spin polarization in semi-insulating GaAs using terahertz time-domain spectroscopy. The results demonstrate that the transmitted and reflected terahertz signals exhibit different dynamic evolutions under the excitation of different polarization laser pulses, indicating the generation and relaxation process of spin-polarized electrons.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Hui Ma, Yaojie Zhu, Yonghai Chen, Chongyun Jiang
Summary: In this study, we investigate the optical tuning of Rashba and Dresselhaus spin-orbit coupling (SOC) through monitoring the spin-galvanic effect (SGE) in a GaAs/Al0.3Ga0.7As two dimensional electron gas. The experimental results reveal different tunabilities of Rashba and Dresselhaus-related SGE currents, and the ratio of their coefficients decreases with the power of the control light, indicating the formation of the inverse persistent spin helix state. Phenomenological and microscopic analysis shows that the Rashba SOC exhibits greater optical tunability compared to the Dresselhaus SOC.
Article
Chemistry, Multidisciplinary
Shuaiqi Li, Jiawei Zhang, Shixue Guan, Ruiang Guo, Duanwei He
Summary: By using the RPPT technique, we have synthesized compact bulk nanocrystalline InAs and confirmed its potential inverse Hall-Petch relation through experimental tests.
Article
Materials Science, Multidisciplinary
Pradeepta Kumar Ghose, Subhadeep Bandyopadhyay, Tamal Kumar Dalui, Jochi Tseng, Jayjit Kumar Dey, Ruchi Tomar, Suvankar Chakraverty, Subham Majumdar, Indra Dasgupta, Saurav Giri
Summary: The bulk Rashba spin splitting and Dirac surface state in (Bi0.9Sb0.1)(2)Se-3 have been reported, which are of great importance for spintronic applications.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Hanchen Wang, Jilei Chen, Tao Yu, Chuanpu Liu, Chenyang Guo, Song Liu, Ka Shen, Hao Jia, Tao Liu, Jianyu Zhang, Marco A. Cabero, Qiuming Song, Sa Tu, Mingzhong Wu, Xiufeng Han, Ke Xia, Dapeng Yu, Gerrit E. W. Bauer, Haiming Yu
Summary: Nanomagnets can be coherently coupled through spin waves for low-power information transmission, which is attractive for analog neuromorphic computing.
Article
Physics, Applied
Ka Shen
Summary: This study investigates magnon spin transport in easy-plane antiferromagnetic insulators, finding that an external magnetic field can compensate for band splitting due to magnetic anisotropy, activating the intrinsic magnon spin Hall effect. This compensation feature allows for field control of magnon spin lifetime and spin diffusion length.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
Yuelin Zhang, Jie Liu, Yongqi Dong, Shizhe Wu, Jianyu Zhang, Jie Wang, Jingdi Lu, Andreas Ruckriegel, Hanchen Wang, Rembert Duine, Haiming Yu, Zhenlin Luo, Ka Shen, Jinxing Zhang
Summary: This study demonstrates the emergence of a strain-driven Dzyaloshinskii-Moriya interaction in a centrosymmetric material, leading to distinct nonreciprocities in spin-wave propagation and the formation of magnetic skyrmion and spiral lattices at room temperature. These results highlight the feasibility of investigating chiral spintronics in a wide range of centrosymmetric magnetic materials.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Lei Wang, Ka Shen, Stepan S. Tsirkin, Tai Min, Ke Xia
Summary: Based on first-principles calculations, a giant crystal-induced transverse current in antiferromagnetic gamma-FeMn is predicted. This abnormal transverse current cannot be explained by conventional anomalous Hall effect and has a high efficiency of generation, making it universal in any crystal with anisotropic symmetry.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Yan Li, Dongxing Zheng, Bin Fang, Chen Liu, Chenhui Zhang, Aitian Chen, Yinchang Ma, Ka Shen, Haoliang Liu, Aurelien Manchon, Xixiang Zhang
Summary: This study reports the unconventional spin pumping and magnetic damping phenomena observed in an insulating compensated ferrimagnet Gd3Fe5O12. The divergence of the nonlocal effective magnetic damping induced by spin pumping close to the compensation temperature in GdIG/Cu/Pt heterostructures is identified, and the coherent and incoherent spin currents generated by spin pumping and the spin Seebeck effect undergo a distinct direction change with the variation of temperature. These findings broaden the conventional paradigm of the ferromagnetic spin pumping model and open new opportunities for exploring ferrimagnetic magnonic devices.
ADVANCED MATERIALS
(2022)
Article
Physics, Applied
Hanchen Wang, Yuben Yang, Marco Madami, Yizhan Wang, Mian Du, Jilei Chen, Yu Zhang, Lutong Sheng, Jianyu Zhang, Chen Wen, Yuelin Zhang, Sijie Hao, Guoqiang Yu, Xiufeng Han, Gianluca Gubbiotti, Ka Shen, Jinxing Zhang, Haiming Yu
Summary: In this study, a giant anisotropy of spin wave propagation in a La0.67Sr0.33MnO3 film grown on different substrates was observed through experimental observation. Interestingly, the decay length and relaxation time of spin waves were found to be largest when the wavevector was along the [110] crystalline orientation, suggesting the potential for individual control of magnetic anisotropy and spin-wave anisotropy through strain engineering.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Huicong Liu, Ka Shen
Summary: This study aims to investigate the effect of magnon polarons on the spin Seebeck effect, and it was found that magnon polarons can enhance or suppress the spin Seebeck effect when the dispersion curve of magnons becomes tangential to that of acoustic phonons. By systematically analyzing the properties of the magnon spectrum in antiferromagnetic materials with varying exchange interaction strength and magnetic anisotropy, the antiferromagnetic materials can be classified based on the number of solutions for the tangential condition between the dispersion curves of magnons and acoustic phonons. Anomalous features were observed in the relatively weak magnetic field regime before the spin flop transition, and a triple-peak feature, never observed or proposed before, was predicted based on the calculation of the longitudinal spin Seebeck coefficient induced by magnon polarons.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Laichuan Shen, Yan Zhou, Ka Shen
Summary: In this work, a spin torque nano-oscillator based on ferrimagnetic skyrmions is proposed, where the current-induced force can be balanced by the controllable Magnus force due to the ferrimagnetic nature. The oscillation frequency relies on the magnetization and can exceed 1.5 GHz around the angular momentum compensation point. This ferrimagnetic nano-oscillator does not require a shaped magnetic working layer, suggesting potential for building oscillator arrays and studying interaction between them.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Hanchen Wang, Marco Madami, Jilei Chen, Hao Jia, Yu Zhang, Rundong Yuan, Yizhan Wang, Wenqing He, Lutong Sheng, Yuelin Zhang, Jinlong Wang, Song Liu, Ka Shen, Guoqiang Yu, Xiufeng Han, Dapeng Yu, Jean-Philippe Ansermet, Gianluca Gubbiotti, Haiming Yu
Summary: We have experimentally observed the spin-wave moirc edge and cavity modes in a nanostructured magnetic moirc lattice. The chiral behavior of the magnon edge modes can be tuned by both the twist angle and the magnetic field. The edge modes emerge within the original magnonic band gap and at the intersection between a mini flatband and a propagation magnon branch.
Article
Materials Science, Multidisciplinary
Ning Zhao, Yihang Duan, Hao Yang, Xue Li, Wen Liu, Jianhua Zhao, Shixuan Han, Ka Shen, Ning Hao, Jiyong Fu, Ping Zhang
Summary: We theoretically achieve flexible control over two copies of persistent spin helix (PSH) by adjusting the Dresselhaus terms and locking the system at a symmetric configuration. We stretch the pitch-spin density wave length of PSH by more than one period, enabling a helix-stretch functional spin field-effect transistor (FET) with protected on and off states. We also introduce the concept of an orbit (band) filter, resembling a spin FET but with the novel functionality of orbit filtering, opening up new possibilities for combined spintronic and orbitronic applications.
Article
Materials Science, Multidisciplinary
Jie Liu, Lin Wang, Ka Shen
Summary: The introduction of effective spin-orbit couplings into magnon systems opens up possibilities to explore novel and intriguing topological phases. In this study, we theoretically investigate the magnon spin-orbit coupling in a layered collinear easy-axis ferrimagnet with dipole-dipole interaction and antiferromagnetic interlayer exchange coupling. We predict the existence of a nodal-loop semimetal phase in the perpendicular magnetization geometry and a Weyl semimetal phase in the lateral magnetization geometry. Additionally, we demonstrate the transformation of the nodal loop into two Weyl points in a noncollinear spin configuration by applying a perpendicular magnetic field. Our findings reveal the significance of noncollinear spin texture in magnon topology and contribute to the study of topological ferrimagnonics.
Article
Materials Science, Multidisciplinary
Laichuan Shen, Yan Zhou, Ka Shen
Summary: We propose a multifunction logic device based on current-driven skyrmion motion, utilizing spatially modulated Dzyaloshinskii-Moriya interaction to create a potential barrier for the skyrmion. Through micromagnetic simulations, we demonstrate three stable stages of the skyrmion location under different magnitudes of driving current, allowing for the implementation of all necessary logic gates for computing applications. Our proposal presents a feasible scheme to design skyrmion-based programmable logic devices.
Article
Materials Science, Multidisciplinary
Andi Cong, Jie Liu, Weishan Xue, Huicong Liu, Yi Liu, Ka Shen
Summary: The interplay between magnons and phonons and its effects on magnon dissipation in a two-dimensional ferromagnet are studied in this work. The relaxation rate of magnons due to exchange-mediated magnon-phonon scatterings is evaluated using first-principles calculations, and rich features in its momentum dependence are revealed. The role of associated phonons with in-plane atomic vibrations is highlighted. Magnon-number-conserving scattering is found to be much stronger than magnon-number-nonconserving scattering. This study provides a better solution for quantitatively evaluating magnon dissipation by phonons.
Article
Materials Science, Multidisciplinary
Ka Shen
Summary: In this study, we use a two-dimensional square lattice model with both magnetic and ferroelectric orders to analyze the role of the Dzyaloshinskii-Moriya interaction in the ground state configuration and quasiparticle excitations. The inverse Dzyaloshinskii-Moriya mechanism stabilizes a spin spiral accompanied by enhanced ferroelectric polarization. Magnons and ferrons, as bosonic excitations of magnetic and ferroelectric orders, are coupled via the dynamical Dzyaloshinskii-Moriya interaction.
Article
Materials Science, Multidisciplinary
Lei Qiu, Ka Shen
Summary: In this paper, the properties of spin waves propagating within magnetic domain walls in a synthetic antiferromagnetic bilayer structure are investigated by micromagnetic simulation. The results demonstrate a giant nonreciprocity in frequency, which can be efficiently controlled by an external magnetic field in terms of both magnitude and sign. The unidirectional excitation of hybridized domain-wall spin waves by a nanostripline antenna is also demonstrated.