Article
Multidisciplinary Sciences
Youcai Han, Changhao Meng, Hong Pan, Jie Qian, Zejin Rao, Liping Zhu, Yongsheng Gui, Can-Ming Hu, Zhenghua An
Summary: This study reports the presence of both reflection BICs (r-BICs) and transmission BICs (t-BICs) in a three-mode cavity magnonics. A generalized framework of non-Hermitian scattering Hamiltonians is developed to explain the observed bidirectional r-BICs and unidirectional t-BICs. An ideal isolation point is found in the complex frequency plane, where the isolation direction can be switched by fine frequency detuning. This work expands the conventional BICs theory and offers a potential for designing functional devices in general wave optics.
Article
Optics
Huili Han, Minglin He, Hao Liu, Bi Zhang, Cong Zhou
Summary: This study investigates the formation mechanism and crystalline orientation effects of damage in ultrafast laser processing of single-crystal diamond. The results show that the damage evolution can be divided into three stages and crystal orientation significantly affects the groove shapes, cracks, and phase transformation. The findings provide a new perspective on ultrafast laser processing of single-crystal diamond, which is crucial for the fabrication of diamond-based functional micro/nano devices with high precision and low damage.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Spectroscopy
Xiangnan Gong, Yingru Wang, Qiongmei Hong, Jie Liu, Chuanyao Yang, Hanjun Zou, Yang Zhou, Dejun Huang, Hong Wu, Zizhen Zhou, Bin Zhang, Xiaoyuan Zhou
Summary: The study on a single crystal of tin selenide (SnSe) using micro-Raman spectroscopy under atmosphere conditions revealed that all vibrational modes remained unchanged, but the peaks red-shifted and softened as the incident laser power increased. A new SnSe2 phase appeared on the crystal surface at high temperature and gradually became dominant.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Physics, Applied
M. A. Morozova, O. Matveev, D. Romanenko, Yu P. Sharaevsky, S. A. Nikitov
Summary: This study investigates the main features of nonlinear spin waves in the magnonic crystal/semiconductor layered heterostructure and demonstrates the potential of double electric and magnetic control over the parameters of gap solitons, bistability of spin waves, switching powers, and nonlinear band gap shift in the structure. The results suggest the possibility of integrating nonlinear magnonics and SC electronics based on the proposed structure.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Applied
Alexandr V. V. Kondrashov, Alexey B. B. Ustinov
Summary: Investigation on the self-generation of microwave nonlinear waveforms in the magnonic-optoelectronic oscillator (MOEO) was conducted. The MOEO's nonlinear dynamics originate from both the optical and magnonic paths of the oscillator circuit. Two unusual waveforms were observed during the transition from regular to chaotic dynamics: symmetry-breaking soliton-like modes of Mobius type and periodic pulses with chaotic amplitude modulation. The nonlinear waveforms were characterized using time series analysis.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Andrey A. Grachev, Alexandr V. Sadovnikov, Sergey A. Nikitov
Summary: In this study, we experimentally investigate the propagation and interaction of spin waves in the double-branched Mach-Zehnder interferometer (MZI) scheme. We show that using a piezoelectric plate with separated electrodes connected to each branch of the MZI allows for tunable interference of the spin-wave signal. Through finite element method and micromagnetic simulations, we explore the impact of distributed deformations on the magnetic properties of the YIG film, and demonstrate the evolution of spin-wave interference patterns under strain induced by an electric field applied to the piezoelectric plate electrodes.
Article
Chemistry, Multidisciplinary
Jian Hu, Sangdu Guo, Bao Fang, Xindong Yu, Zhiqiang Gu, Gangyan Li
Summary: This study investigates the impact of laser processing on the natural frequency adjustment of a micro crystal resonator (MCR) and designs a laser processing control system suitable for frequency modulation. The laser processing parameters are optimized through orthogonal experiments.
APPLIED SCIENCES-BASEL
(2022)
Article
Nanoscience & Nanotechnology
Fabio Isa, James P. Best, Anna Marzegalli, Marco Albani, Christophe Comte, Jamie J. Kruzic, Avi Bendavid
Summary: A novel approach is presented in this paper to tailor the stress properties of diamond thin films through boron doping and micro-fabrication of bridges using focused ion beam milling. Experimental data, supported by detailed confocal micro-Raman investigations and finite element method calculations, suggest that appropriate design of microbridge geometries, together with boron doping, can significantly enhance or diminish material stress compared to non-patterned thin films. This approach, combined with deterministic incorporation and positioning of diamond color centers, may offer new opportunities to tailor the optical and spin properties of diamond-based quantum devices through stress engineering.
Article
Optics
Wen-Ze Xue, Zhang-Lang Lin, Huang-Jun Zeng, Ge Zhang, Peixiong Zhang, Zhenqiang Chen, Zhen Li, Valentin Petrov, Pavel Loiko, Xavier Mateos, Haifeng Lin, Yongguang Zhao, Li Wang, Weidong Chen
Summary: We report on the continuous-wave and mode-locked laser performance of Yb3+-doped yttrium-gadolinium orthoaluminate crystal. The maximum output power in the continuous-wave regime was 429 mW at 1041.8 nm with a slope efficiency of 51.1% and a wavelength tuning range of 84 nm (1011-1095 nm). The self-starting mode-locked operation using a semiconductor saturable absorber mirror produced soliton pulses as short as 43 fs.
Article
Nanoscience & Nanotechnology
Arundhati Adhikari, Sudip Majumder, YoshiChika Otani, Anjan Barman
Summary: Bicomponent magnonic crystals (BMCs) are metasurfaces formed using two dissimilar materials, which enable a richer manipulation of spin waves for spin-wave based computation and communication. The interplay between Co50Fe50 and Ni80Fe20 in a BMC is studied, and the interface engineered coupling is combined with long-range dipolar coupling. Systematic variation of the filling fraction of Co50Fe50 and Ni80Fe20 in the BMC tunes these couplings, and the spin-wave spectra are highly sensitive to the bias-field strength. Numerical simulations demonstrate long-distance and high-speed spin-wave propagation controlled by the filling fraction and a diode-like on/off mechanism determined by the applied magnetic field strength. These observations contribute to the development of high-speed reconfigurable magnonic devices controlled by external parameters.
ACS APPLIED NANO MATERIALS
(2023)
Article
Multidisciplinary Sciences
Sho Watanabe, Vinayak S. Bhat, Korbinian Baumgaertl, Mohammad Hamdi, Dirk Grundler
Summary: The study reports a two-dimensional magnonic quasicrystal formed on ferrimagnetic yttrium iron garnet, with phase-resolved spin wave imaging at gigahertz frequencies showing multidirectional emission and partial forbidden gaps.
Article
Physics, Multidisciplinary
Khalil Zakeri, Huajun Qin, Arthur Ernst
Summary: The article discusses the formation and effects of magnonic surface and interface states in layered ferromagnets, showcasing experimental examples and suggesting potential characteristics. The authors also propose the possibility of customizing these states through artificial fabrication.
COMMUNICATIONS PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Ankang Liu, Alexander M. Finkel'stein
Summary: The magnonic crystal can generate a band gap using alternating current (ac) instead of direct current (dc), with the size of the gap depending on the frequency of the ac modulation and the dispersion of the spin wave. The resulting gap in the ac magnonic crystal is half the size of the one in the dc magnonic crystal with the same modulation amplitude.
Article
Materials Science, Multidisciplinary
Z. R. Yan, Y. W. Xinga, X. F. Hana
Summary: This research explores the resonant tunneling effect in magnonic crystals, demonstrating a similar effect to a Fabry-Perot interferometer and showing potential for band-pass magnonic filters. The use of an inverse design approach and particle swarm algorithm allows for automatic finding of optimized parameters with high computing efficiency.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Optics
Zeng-Xing Liu, Jiao Peng, Hao Xiong
Summary: Due to the weak non-linear interaction of magnons, it is difficult to generate a wide-bandwidth magnonic frequency comb under low power drive. This study presents an efficient mechanism for the generation of a wide-bandwidth magnonic frequency comb via a two-tone microwave driving in a magnomechanical system. Numerical simulations show that the magnetostrictive effect can be greatly enhanced by the beat frequency signal from the two-tone microwave driving field, and a robust magnonic frequency comb can be observed at low power.
Article
Chemistry, Multidisciplinary
Hendrik Meer, Stephan Wust, Christin Schmitt, Paul Herrgen, Felix Fuhrmann, Steffen Hirtle, Beatrice Bednarz, Adithya Rajan, Rafael Ramos, Miguel Angel Nino, Michael Foerster, Florian Kronast, Armin Kleibert, Baerbel Rethfeld, Eiji Saitoh, Benjamin Stadtmueller, Martin Aeschlimann, Mathias Klaeui
Summary: The antiferromagnetic order in NiO/Pt thin film heterostructures can be altered by optical pulses. Using X-ray magnetic linear dichroism, the optically induced creation of antiferromagnetic domains can be visualized. The effect of different laser polarizations on domain formation can be studied to identify polarization-independent creation of 180 degrees domain walls and domains with different Neel vector orientations. By varying irradiation parameters, the switching mechanism was determined to be thermally induced. This study demonstrates the potential for optically creating antiferromagnetic domains, an important advancement in the functionalization of all optical switching mechanisms in antiferromagnets.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
Miku Yoshida, Md. Riad Kasem, Aichi Yamashita, Ken-ichi Uchida, Yoshikazu Mizuguchi
Summary: Recently, researchers have been studying thermal switching as an important component for thermal management in electronic devices. In this study, a significant magneto-thermal-switching ratio (MTSR) was observed in pure Nb at temperatures below its superconducting transition temperature. The MTSR increased as the temperature decreased, reaching 650% at a temperature of 2.5 K and a magnetic field of 4.0 kOe. The thermal switching in superconductors with a large MTSR could greatly enhance the performance of low-temperature electronic devices.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
Sohei Horibe, Hiroki Shimizu, Koujiro Hoshi, Takahiko Makiuchi, Tomosato Hioki, Eiji Saitoh
Summary: Parametric oscillation occurs when the resonance frequency of an oscillator is periodically modulated. Owing to time-reversal symmetry breaking in magnets, nonreciprocal magnons can be parametrically excited when spatial-inversion symmetry breaking is provided. We demonstrate switching on and off the magnon parametric oscillation by reversing the external field direction applied to a Y3Fe5O12 micro-structured film. The result originates from the nonreciprocity of surface mode magnons, leading to field-direction dependence of the magnon accumulation under nonuniform microwave pumping. Our numerical calculation well reproduces the experimental result.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
Weinan Zhou, Asuka Miura, Takamasa Hirai, Yuya Sakuraba, Ken-ichi Uchida
Summary: Seebeck-driven transverse thermoelectric generation (STTG) was investigated in magnetic/thermoelectric hybrid materials. The transverse thermopower in a ferromagnetic Co2MnGa/thermoelectric n-type Si hybrid bulk material reached 16.0 lV/K at room temperature, which is much larger than the anomalous Nernst coefficient of the Co2MnGa slab (6.8 lV/K). Although the transverse thermopower is smaller compared to thin-film-based hybrid materials, the hybrid bulk materials exhibit larger electrical power due to their small internal resistance. This study confirms the validity of STTG in bulk materials and highlights its potential as a thermal energy harvester.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Atsushi Takahagi, Ryo Iguchi, Hosei Nagano, Ken-ichi Uchida
Summary: We find that the temperature measurement sensitivity in LITR can be improved by incorporating a thermochromic liquid crystal (TLC) into a transducer. The estimated thermoreflectance coefficient of a TLC/Pt hybrid film reaches >2 x 10(-2) K-1 at low excitation frequencies, which is two orders of magnitude greater than typical metallic films. Using the TLC/Pt film, we were able to detect temperature changes with a resolution of about 10 μK due to Joule heating and the spin Peltier effect, surpassing the resolution achieved with an Au film despite the lower reflected light intensity of the TLC/Pt film.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Ryo Iguchi, Daisuke Fukuda, Jun Kano, Takashi Teranishi, Ken-ichi Uchida
Summary: We present a direct measurement method for electrocaloric effects in dielectric materials based on lock-in thermography technique. The method utilizes sinusoidal excitation and multi-harmonic detection to measure the actual temperature change in the frequency domain, even when the electrocaloric effect exhibits a nonlinear response. We demonstrated the method by measuring the temperature dependence of electric-field-induced temperature change in Sr-doped BaTiO3 systems and extracting the pure electrocaloric contribution free from heat losses and Joule heating.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Takahiro Chiba, Ryo Iguchi, Takashi Komine, Yasuhiro Hasegawa, Ken-ichi Uchida
Summary: The Thomson effect can induce heat release or absorption in conductors when a charge current and a temperature gradient are simultaneously applied. In this study, we investigate the temperature distribution due to the Thomson-effect-induced heat release/absorption in junctionless single conductors, which can act as a temperature modulator. We also analyze the temperature distribution in realistic conductors. Our findings show that for conductors with a large Thomson coefficient, the temperature derivative of the Seebeck coefficient and the Thomson-effect-induced heat absorption can overcome Joule heating, resulting in current-induced cooling in the bulk region. We also demonstrate the feedback effect of the Thomson effect, which stabilizes the system temperature to one side of the heat bath, indicating the dependence of the Thomson effect on position and local temperature gradient. This work lays the foundation for thermal management utilizing the Thomson effect.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
K. K. Meng, J. K. Chen, Y. Wu, X. G. Xu, T. Kikkawa, L. P. Sun, D. Z. Hou, Q. Li, N. N. Zhang, Z. G. Fu, T. Zhu, Y. Jiang, E. Saitoh
Summary: In this study, the quantum correction to the anomalous Hall effects (AHEs) in magnetic PtMnGe (PMG) thin films was investigated. It was found that the quantum correction to the transport behavior in the two-dimensional PMG system remains robust, even in the presence of spin-dependent scattering.
Article
Chemistry, Physical
Chanho Park, Jae Won Choi, No-Won Park, Gil-Sung Kim, Takashi Kikkawa, Eiji Saitoh, Sang-Kwon Lee
Summary: Recently, efforts have been made to improve the spin-voltage in Pt/Y3Fe5O12 (Pt/YIG) structures by inserting thin ferromagnetic interlayers, such as monolayer transition metal dichalcogenide (TMDC) layers. However, the role of monolayer TMDC interlayers in Pt/YIG systems and their temperature dependence remain unexplored. In this study, we investigated the temperature-dependent longitudinal spin Seebeck effect (LSSE) in Pt/YIG bilayer and Pt/ML MoS2/YIG trilayer systems. Our findings indicate that the inverse spin Hall effect (ISHE) voltages of Pt/ML MoS2/YIG are significantly lower compared to Pt/YIG system, due to the magnetic selection rule and diamagnetic ML MoS2 interlayer hindering the movement of spins generated at the interface in Pt/YIG structure.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Hiroto Adachi, Naoshi Ikeda, Eiji Saitoh
Summary: In comparison to transport of spin polarization in ferromagnets, transport of electric polarization in ferroelectrics remains less explored. Taking an excitonic insulator model of electronic ferroelectricity as a prototypical example, we theoretically investigate the low-energy dynamics and transport of electric polarization by microscopically constructing the Ginzburg-Landau action. We show that, because of the scalar nature of the excitonic order parameter, only the longitudinal fluctuations are relevant to the transport of electric polarization. We also formulate the electric-polarization diffusion equation, in which the electric-polarization current is defined purely electronically without recourse to the lattice degrees of freedom.
Article
Materials Science, Multidisciplinary
C. Schmitt, L. Sanchez-Tejerina, M. Filianina, F. Fuhrmann, H. Meer, R. Ramos, F. Maccherozzi, D. Backes, E. Saitoh, G. Finocchio, L. Baldrati, M. Klaeui
Summary: In this study, we demonstrate that arbitrary-shaped T domains can be generated in antiferromagnetic NiO/Pt bilayers through switching driven by electrical current pulses. The domain walls between the T domains have spins pointing towards the average direction of the two T domains, indicating the absence of strong Lifshitz invariants. The micromagnetic modeling suggests that the domain wall is formed by strain distributions in the NiO thin film induced by the MgO substrate.
Article
Materials Science, Multidisciplinary
Hiroki Arisawa, Shunsuke Daimon, Yasuyuki Oikawa, Takashi Kikkawa, Eiji Saitoh
Summary: The spatial dependence of magnetization dynamics in a Y3Fe5O12 film under a magnetic-field gradient is investigated using local spin pumping and inverse spin-Hall effects. The results show that when microwaves are irradiated locally, magnetization precession is excited at a distant position from the irradiation location. By analyzing the field and microwave frequency dependence, it is found that the observed magnetization dynamics are due to nonlocal resonance of magnetization and spatial changes in spin-wave dispersion under the magnetic-field gradient, suggesting the potential to realize a microwave spectrometer known as a spin-wave cochlea.
Article
Materials Science, Multidisciplinary
Koichi Oyanagi, Saburo Takahashi, Takashi Kikkawa, Eiji Saitoh
Summary: We have theoretically studied the spin Seebeck effect (SSE) in a bilayer system of normal metal (NM) and paramagnetic insulator (PI). By considering the spin-flip scattering through interfacial exchange coupling, we calculated the thermal spin pumping from PI to NM and backflow spin current from NM to PI using a linear response approach. Our results show the appearance of a finite spin current at the interface under a temperature difference between spins in NM and PI, which increases with the density of localized spin S. Additionally, our model successfully explains the experimentally observed reduction of paramagnetic SSE in Pt/Gd3Ga5O12 when the Zeeman energy is comparable to the thermal energy.