Article
Materials Science, Multidisciplinary
Ville A. J. Pyykkonen, Sebastiano Peotta, Philipp Fabritius, Jeffrey Mohan, Tilman Esslinger, Paivi Torma
Summary: This theoretical study focuses on transport through a finite-size sawtooth lattice coupled to fermionic reservoirs in a superfluid state. It reveals that flat-band states support larger critical current and temperature than dispersive band states, requiring tuning of the boundary states at resonance with the flat-band states. The two-terminal configuration transport can show the linear dependence of key quantities on interaction strength, reflecting the geometric contribution of flat-band superconductivity.
Article
Multidisciplinary Sciences
Ruigang Li, Lei Chen, Jun-Feng Liu, Jun Wang
Summary: This study investigates the crossed Andreev reflection in a ferromagnet/superconductor/ferromagnet junction based on zigzag phosphorene nanoribbons. By properly setting electric potentials, the maximal nonlocal conductance can be achieved and the local Andreev reflection and electron tunneling can be eliminated. The nonlocal conductance oscillates with the length and electric potential of the superconductor.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Daniel Z. Haxell, Marco Coraiola, Manuel Hinderling, Sofieke C. ten Kate, Deividas Sabonis, Aleksandr E. Svetogorov, Wolfgang Belzig, Erik Cheah, Filip Krizek, Ruediger Schott, Werner Wegscheider, Fabrizio Nichele
Summary: We performed measurements on planar Josephson junctions with independent control over the two superconducting phase differences and observed an anomalous phase shift in the current-phase relation of one junction as a function of gate voltage or phase difference in the other junction. This demonstrates the nonlocal Josephson effect and the implementation of a tunable f(0)-junction. The anomalous phase shift is more significant at shorter distances between the junctions and disappears for distances much longer than the superconducting coherence length. The results indicate the formation of an Andreev molecule through the hybridization of Andreev bound states. The devices could serve as tunable superconducting phase sources and enable new coupling schemes for hybrid quantum devices.
Article
Physics, Applied
T. E. Golikova, M. J. Wolf, D. Beckmann, G. A. Penzyakov, I. E. Batov, I. Bobkova, A. M. Bobkov, V. V. Ryazanov
Summary: In nanofabricated planar crosslike S-N/F-S Josephson structures, a nonmonotonic dependence of the critical Josephson supercurrent on the injection current has been observed experimentally. This behavior is believed to be caused by the interaction between N and F layers.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Applied
Chao Chen, Biao Jin
Summary: Using the Green's function method, this study theoretically investigates the Josephson effect and pair correlations in an s-wave Josephson junction with a ferromagnetic trilayer. The critical Josephson current is found to be sensitively dependent on the angle between the exchange fields in the ferromagnetic layers. The results suggest a strong correlation between the critical Josephson current and the spin-triplet correlation, highlighting the importance of the spin-triplet proximity effect in the SF1F2F1S systems.
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
(2021)
Article
Chemistry, Multidisciplinary
A. T. Costa, Mikhail I. Vasilevskiy, J. Fernandez-Rossier, Nuno M. R. Peres
Summary: This article investigates the challenges of forming hybrid plasmon-magnon polaritons in heterostructures and demonstrates the possibility of polaritons formed by graphene plasmons and magnons in two-dimensional ferromagnetic insulators.
Article
Chemistry, Multidisciplinary
Jongyun Lee, Wonjun Lee, Gi-Yeop Kim, Yong-Bin Choi, Jinho Park, Seong Jang, Genda Gu, Si-Young Choi, Gil Young Cho, Gil-Ho Lee, Hu-Jong Lee
Summary: The research found that the anisotropic superconducting order parameters in twisted Bi-2212 vdW junctions exhibit different Josephson couplings at different twist angles, with the maximum coupling occurring at 0 degrees and 90 degrees twist angles. The twist angle dependence of the Josephson coupling was quantitatively explained by theoretical calculations, revealing the anisotropic nature of Bi-2212 and providing a novel fabrication technique compatible with air-sensitive vdW materials.
Article
Materials Science, Multidisciplinary
Yu M. Shukrinov, I. R. Rahmonov, A. Janalizadeh, M. R. Kolahchi
Summary: We study the phase dynamics, IV characteristics, and magnetization dynamics of the phi(0) Josephson junction at small values of spin-orbit interaction, ratio of the Josephson junction to magnetic energy, and Gilbert damping. We demonstrate that the coupled Landau-Lifshitz-Gilbert-Josephson dynamics can be reduced to a scalar nonlinear Duffing oscillator. An anomalous shift of the ferromagnetic resonance frequency with decreasing Gilbert damping is found. There is a critical damping value at which nonlinearity comes into play and changes the damping dependence of the ferromagnetic resonance.
Article
Materials Science, Multidisciplinary
Fumikazu Oguro, Yudai Sato, Kanta Asakawa, Masahiro Haze, Yukio Hasegawa
Summary: The study found that steps in the Si(111)-root 3 x root 43 Pb reconstructed structure significantly disrupt the electronic states of the superconducting atomic layer and hold Josephson-like vortices under the out-of-plane magnetic field. Monolayer superconductors exhibit unique properties under different magnetic field directions, providing potential for superconducting materials with high tolerance against magnetic fields.
Article
Multidisciplinary Sciences
Chun-Guang Chu, Jing-Jing Chen, An-Qi Wang, Zhen-Bing Tan, Cai-Zhen Li, Chuan Li, Alexander Brinkman, Peng-Zhan Xiang, Na Li, Zhen-Cun Pan, Hai-Zhou Lu, Dapeng Yu, Zhi-Min Liao
Summary: We report the observation of broad edge supercurrent in Dirac semimetal Cd3As2-based Josephson junctions. The wide and large edge supercurrent, as well as the nonlocality, suggest the presence of non-Hermitian skin effect. The interplay between band topology and non-Hermiticity is beneficial for exploiting exotic topological matter.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Chun-Guang Chu, Jing-Jing Chen, An-Qi Wang, Zhen-Bing Tan, Cai-Zhen Li, Chuan Li, Alexander Brinkman, Peng-Zhan Xiang, Na Li, Zhen-Cun Pan, Hai-Zhou Lu, Dapeng Yu, Zhi-Min Liao
Summary: In this study, broad edge supercurrent is observed in Dirac semimetal Cd3As2-based Josephson junctions, indicating the presence of non-Hermitian skin effect. The wide and large edge supercurrent, as well as the observed supercurrent nonlocality, suggest the interplay between band topology and non-Hermiticity in exploiting exotic topological matter.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Shahrukh Salim, Rahul Marathe, Sankalpa Ghosh
Summary: In this study, we compare the theory with experimental results on charge transport through Josephson junctions made of graphene. A transfer matrix approach is used to analytically derive the spectrum of Andreev bound states (ABS) in a superconductor-graphene-superconductor junction, focusing on monolayer graphene. The theoretical results successfully explain both the retro Andreev reflection (RAR) and specular Andreev reflection (SAR) phenomena within the relevant parameter range. By evaluating the current and conductance using the ABS spectrum and experimental system parameters, we find good agreement with experimental results, with the calculated values showing scaling behavior with junction length and significantly lower values when RAR is dominant.
Article
Chemistry, Multidisciplinary
Haozhe Wang, Xianghan Xu, Danrui Ni, David Walker, Jie Li, Robert J. Cava, Weiwei Xie
Summary: This study reports the high-pressure synthesis and ambient-pressure characterization of hexagonal HP-BaCoO3. The material has a 2H crystal structure and a short Co-Co distance. Magnetization investigation shows robust diamagnetic behavior below approximately 130 K and a distinct half-levitation phenomenon below that temperature. However, its field-dependent magnetization profile indicates characteristics of ferromagnetism with substantial magnetic retentivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Quantum Science & Technology
Ranran Cai, Igor Zutic, Wei Han
Summary: This article reviews the important research progress of superconductor/ferromagnet (SC/FM) heterostructures, including spin-triplet superconductivity, superconducting order parameter oscillation, and topological superconductivity. These heterostructures have unique physical properties, making them promising platforms for future superconducting spintronics and quantum computation applications.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Eyal Walach, Efrat Shimshoni
Summary: The research reveals that interactions and disorder in low-dimensional superconductors can lead to the formation of multiple quantum phases at a quantum critical point, with a key feature being the perfect Z(2) symmetry. The study of weak disorder on a two-leg Josephson ladder model has identified at least one intermediate phase between a full-fledged superconductor and a disorder-dominated insulator, with the presence of two distinct mixed phases.
Article
Physics, Applied
Y. Tsutsumi, S. Maekawa
Summary: The coupling of spin angular momentum and mechanical rotation in liquid helium-3 generates a nuclear spin current through the Stern-Gerlach effect. The effective field gradient, estimated quantitatively based on the microscopic Boltzmann equation, is large enough to be detected in NMR measurements. This study demonstrates the potential of utilizing the spin-rotation coupling for controlling and detecting spin currents in liquid helium-3.
JOURNAL OF LOW TEMPERATURE PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Hideki Matsuoka, Stewart Edward Barnes, Jun'ichi Ieda, Sadamichi Maekawa, Mohammad Saeed Bahramy, Bruno Kenichi Saika, Yukiharu Takeda, Hiroki Wadati, Yue Wang, Satoshi Yoshida, Kyoko Ishizaka, Yoshihiro Iwasa, Masaki Nakano
Summary: This research presents strong out-of-plane magnetic anisotropy at the interface between two different vdW materials, and proposes a simple model to explain the observations. These results demonstrate a new magnetic proximity effect at the vdW interface, expanding the horizons of emergent phenomena achievable in vdW heterostructures.
Article
Physics, Multidisciplinary
Florian Lange, Satoshi Ejima, Junji Fujimoto, Tomonori Shirakawa, Holger Fehske, Seiji Yunoki, Sadamichi Maekawa
Summary: Using unbiased large-scale time-dependent density-matrix renormalization-group simulations, we have demonstrated the generation of a charge-current vortex via spin injection in the Rashba system. The spin current is polarized perpendicular to the system plane and injected from an attached antiferromagnetic spin chain. We discuss the conversion between spin and orbital angular momentum in the current vortex and predict the electromagnetic field accompanying the vortex for possible future experiments.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Michiyasu Mori, Sadamichi Maekawa
Summary: The study investigates a superconducting quantum interference device (SQUID) with 0- and pi-Josephson junctions (JJs), known as pi-SQUID, using the resistively shunted junction model. It demonstrates that the pi-SQUID exhibits half-integer Shapiro steps (SS) under microwave irradiation, making it a potential pi-qubit with spontaneous loop currents. The equivalence of 0- and pi-JJs is crucial for achieving the half-integer SS and realizing the pi-qubit.
APPLIED PHYSICS EXPRESS
(2021)
Article
Physics, Multidisciplinary
Hiroyuki Chudo, Masaki Imai, Mamoru Matsuo, Sadamichi Maekawa, Eiji Saitoh
Summary: The study demonstrates the observation of the angular momentum compensation temperature (TA) in ferrimagnets, determining it to be 240K in the Ho3Fe5O12 system. The increase of TA with Dy content is shown, with Ho1.5Dy1.5Fe5O12 corresponding to room temperature. Fe-57-NMR measurements are used to explore domain wall dynamics in HoIG, revealing an enhancement of NMR signal at TA due to increased domain-wall mobility.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2021)
Article
Nanoscience & Nanotechnology
Junji Fujimoto, Florian Lange, Satoshi Ejima, Tomonori Shirakawa, Holger Fehske, Seiji Yunoki, Sadamichi Maekawa
Summary: By utilizing response theory, the paper calculates the charge current vortex generated by spin pumping at a point-like contact in a system with Rashba spin-orbit coupling. The oscillatory behavior of the charge current as a function of distance from the spin pumping source is observed, which is supported by numerical simulations. The introduction of the SOC Hamiltonian on the lattice as the generator of the spin current is a significant aspect of their calculations.
Article
Engineering, Electrical & Electronic
Junji Fujimoto, Hiroshi Funaki, Wataru Koshibae, Mamoru Matsuo, Sadamichi Maekawa
Summary: Motivated by a recent experiment, this study examines the interaction between electric current vorticity and localized spins in FeGe devices, revealing three effects: the induction of an effective Zeeman field, a vorticity-induced Dzyaloshinskii-Moriya interaction, and a spin current driven by the vorticity gradient. These findings open up a new path for designing magnetic textures using structural settings.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Multidisciplinary Sciences
Jianyu Zhang, Mingfeng Chen, Jilei Chen, Kei Yamamoto, Hanchen Wang, Mohammad Hamdi, Yuanwei Sun, Kai Wagner, Wenqing He, Yu Zhang, Ji Ma, Peng Gao, Xiufeng Han, Dapeng Yu, Patrick Maletinsky, Jean-Philippe Ansermet, Sadamichi Maekawa, Dirk Grundler, Ce-Wen Nan, Haiming Yu
Summary: In multiferroic heterostructures, researchers have demonstrated a millimeter-long magnon decay length, solving a long-standing issue in metallic magnets. This magnon transport method shows potential for low-power computation.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Applied
J. Puebla, Y. Hwang, S. Maekawa, Y. Otani
Summary: Surface acoustic waves (SAWs) are elastic waves propagating on the surface of solids with the amplitude decaying into the solid. SAWs can manipulate the magnetization states by magnetostriction and magnetoelastic effects. This review discusses the characteristics of SAW devices and their interaction with the magnetization in thin films.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Kei Yamamoto, Mingran Xu, Jorge Puebla, Yoshichika Otani, Sadamichi Maekawa
Summary: In this paper, a theoretical description of magnon-phonon interactions in multilayer structures containing a ferromagnetic thin film is presented. The formalism takes into account external magnetic fields in arbitrary directions and various types of acoustic waves, including Rayleigh and Love surface modes. By paying attention to the spatial profile of acoustic wave modes and deriving analytical expressions for effective coupling coefficients, the study successfully reproduces a strongly anisotropic and non-reciprocal linewidth observed in recent experiments of acoustic ferromagnetic resonance.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Multidisciplinary
Hakuto Suzuki, Guoqiang Zhao, Jun Okamoto, Shoya Sakamoto, Zhi-Yin Chen, Yosuke Nonaka, Goro Shibata, Kan Zhao, Bijuan Chen, Wen-Bin Wu, Fan-Hsiu Chang, Hong-Ji Lin, Chien-Te Chen, Arata Tanaka, Masaki Kobayashi, Bo Gu, Sadamichi Maekawa, Yasutomo J. Uemura, Changqing Jin, Di-Jing Huang, Atsushi Fujimori
Summary: The magnetic properties and electronic excitations of Ba1-xKx(Zn1-yMny)2As2, a new diluted magnetic semiconductor, were studied using x-ray magnetic circular dichroism (XMCD) and resonant inelastic x-ray scattering (RIXS) techniques. The findings revealed that Mn atoms are in a high-spin configuration of d5, but the net spin moment is reduced due to the presence of competing ferromagnetic and antiferromagnetic interactions between Mn ions. RIXS spectra showed broad peaks originating from d-d crystal field excitations of Mn ions. Comparison with Ga1-xMnxAs indicated that the ground state of Mn in Ba1-xKx(Zn1-yMny)2As2 consists of both charge-transferred electron configuration and pure configuration with free holes.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2022)
Article
Materials Science, Multidisciplinary
Yunyan Yao, Ranran Cai, See-Hun Yang, Wenyu Xing, Yang Ma, Michiyasu Mori, Yuan Ji, Sadamichi Maekawa, Xin-Cheng Xie, Wei Han
Summary: This study reports the experimental observation of half-integer Shapiro steps in a strong ferromagnetic Josephson junction, showing robustness in a wide temperature range. The formation of these steps is attributed to the coexistence of 0 and pi states in the NiFe junction. This conclusion is supported by high-resolution transmission electron microscopy characterization of the junction materials.
Article
Materials Science, Multidisciplinary
Junji Fujimoto, Wataru Koshibae, Mamoru Matsuo, Sadamichi Maekawa
Summary: The research demonstrates a Dzyaloshinskii-Moriya interaction driven by electric current vorticity, allowing for control of magnetic skyrmion creation and annihilation without an external magnetic field. The direction of the current and structural settings offer different possibilities for studying magnetic textures.
Article
Materials Science, Multidisciplinary
H. Chudo, M. Matsuo, S. Maekawa, E. Saitoh
Summary: Using the rotating nuclear quadrupole resonance (NQR) method, we observed the Barnett field, rotational Doppler effect, and Berry phase, and studied the different NQR line splittings in various setups. Analyzing these spectral structures allowed us to clarify the origins of NQR line splittings and discuss the relationship between rotational Doppler effect, Barnett field effect, and Berry phase. Additionally, we provided clear evidence of the differences between rotational Doppler effect and Barnett field, and the equivalence of Barnett field and Berry phase.
Article
Engineering, Electrical & Electronic
Shoya Sakamoto, Guoqiang Zhao, Goro Shibata, Zheng Deng, Kan Zhao, Xiancheng Wang, Yosuke Nonaka, Keisuke Ikeda, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Tsuneharu Koide, Arata Tanaka, Sadamichi Maekawa, Yasutomo J. Uemura, Changqing Jin, Atsushi Fujimori
Summary: The study investigates the perpendicular magnetic anisotropy of a layered ferromagnetic semiconductor using angle-dependent X-ray magnetic circular dichroism measurements. The large magnetic anisotropy is attributed to the anisotropic distribution of Mn 3d electrons and the lifting of degeneracy of p-d(xz), d(yz) hybridized states.
ACS APPLIED ELECTRONIC MATERIALS
(2021)