Article
Multidisciplinary Sciences
Anne Bernand-Mantel, Cyrill B. Muratov, Valeriy V. Slastikov
Summary: In this study, the continuum micromagnetic framework is used to derive formulas for compact skyrmion lifetime in ultrathin ferromagnetic films. The formulas take into account the effect of thermal noise and the relatively weak interfacial Dzyaloshinskii-Moriya interaction. When there is no saddle point connecting the skyrmion solution to the ferromagnetic state, the skyrmion collapse event is interpreted as capture by a microscale absorber.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Applied
Yao Zhang, Guy Dubuis, Colin Doyle, Tane Butler, Simon Granville
Summary: Magnetic skyrmions, nanoscale topological spin textures, show great potential in spintronics applications. Ionic liquid gating is a versatile method that can be used to generate and tune skyrmions by modifying the magnetic characteristics of thin films. The results demonstrate the ability to engineer both nonvolatile and volatile skyrmions through reversible changes in the film's magnetic characteristics.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Multidisciplinary
Shuai Yuan, Zuhuang Chen, Sergei Prokhorenko, Yousra Nahas, Laurent Bellaiche, Chenhan Liu, Bin Xu, Lang Chen, Sujit Das, Lane W. Martin
Summary: Using phase-field simulations, the evolution of polar topology and the emergence of a hexagonal close-packed skyrmion lattice in ultrathin ferroelectric PbTiO3 films is explored. The lattice can be stabilized under an external electric field and the lattice constants increase with film thickness. These studies pave the way for the development of novel ordered condensed matter phases in nanoscale ferroelectrics.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yifan Zhou, Rhodri Mansell, Tapio Ala-Nissila, Sebastiaan van Dijken
Summary: This paper studies the thermally activated motion of arrays of magnetic skyrmions and their interaction with grain boundaries, showing that grain boundaries can either reduce or enhance the diffusion coefficient of the skyrmions depending on the lag time, grain size, and magnetic anisotropy.
Article
Chemistry, Physical
Viet Duc Duong, Phuoc Cao Van, Trinh Nguyen Thi, Ha Yeong Ahn, Viet Anh Cao, Junghyo Nah, Ganghwi Kim, Ki-Suk Lee, Ji-Wan Kim, Jong-Ryul Jeong
Summary: In this study, we investigated the magnetic properties of thulium iron garnet (TmIG) thin films grown on gadolinium gallium garnet (GGG) substrates. We controlled the annealing temperature, thickness, and roughness of the films to achieve perpendicular magnetic anisotropy (PMA) and large coercive field, important for non-volatile magnetic memory device applications. The results showed that the annealing temperature was a crucial parameter for controlling the film surface quality and engineering the direction of magnetic anisotropy. By further optimizing the film thickness, we achieved the best condition for PMA films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Amal Aldarawsheh, Moritz Sallermann, Muayad Abusaa, Samir Lounis
Summary: Topological antiferromagnetism is a vibrant research field aiming to identify topologically protected magnetic states. This study predicts new chiral particles, exchange-frustrated multimeronic spin textures, hosted by a Ne'el magnetic state in single AFM materials. These structures have distinct topological charges and enhanced stability against external magnetic fields.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Multidisciplinary Sciences
Xiaoqian Zhang, Qiangsheng Lu, Wenqing Liu, Wei Niu, Jiabao Sun, Jacob Cook, Mitchel Vaninger, Paul F. Miceli, David J. Singh, Shang-Wei Lian, Tay-Rong Chang, Xiaoqing He, Jun Du, Liang He, Rong Zhang, Guang Bian, Yongbing Xu
Summary: Growth and properties of single- and few-layer CrTe2 on bilayer graphene by molecular beam epitaxy (MBE) have shown intrinsic ferromagnetism with a Curie temperature up to 300 K and perpendicular magnetic anisotropy, providing a new avenue for developing large-scale 2D magnet-based spintronics devices.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
R. Brearton, L. A. Turnbull, J. A. T. Verezhak, G. Balakrishnan, P. D. Hatton, G. van der Laan, T. Hesjedal
Summary: Magnetic skyrmions are topologically non-trivial magnetic moments that form lattices in helimagnetic materials, showing promise as efficient information carriers. The skyrmion Hall angle, which measures the deviation of skyrmion motion from the driving force, can be determined using reciprocal space techniques. Skyrmions experience deflection under a shear drive, leading to an additional sideways motion known as the skyrmion hall effect.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Applied
Xiaoye Chen, Edwin Chue, Jian Feng Kong, Hui Ru Tan, Hang Khume Tan, Anjan Soumyanarayanan
Summary: In this study, the temperature dependence of the stripe-to-skyrmion transition in Co/Pt-based multilayers was investigated experimentally and theoretically. The results reveal the increased efficacy of stripe-to-skyrmion fission at higher temperatures, primarily due to the thermal evolution of key magnetic interactions, leading to enhanced skyrmion density. Atomistic calculations elucidate that the energy barrier to fission governs the thermodynamics of skyrmion formation. This research advances the understanding of the mechanism behind the stripe-to-skyrmion transition and promotes the use of thermal knobs for efficient skyrmion generation.
PHYSICAL REVIEW APPLIED
(2022)
Article
Engineering, Electrical & Electronic
Youhua Feng, Xi Zhang, Guoping Zhao, Gang Xiang
Summary: This study demonstrates that the skyrmion Hall effect can be utilized to design a useful skyrmion diode, providing a promising pathway for the development of spintronic devices based on unidirectional skyrmion transport.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Nanoscience & Nanotechnology
Valentin Ahrens, Luca Gnoli, Domenico Giuliano, Simon Mendisch, Martina Kiechle, Fabrizio Riente, Markus Becherer
Summary: This article evaluates the effects of FIB Ga+ irradiation on skyrmion motion in W/CoFeB/MgO thin films, revealing that the speed and angle of motion of the magnetic textures significantly decrease in the irradiated zone.
Article
Materials Science, Multidisciplinary
Sujit Panigrahy, Sougata Mallick, Joao Sampaio, Stanislas Rohart
Summary: We study the behavior of magnetic skyrmions in synthetic antiferromagnets with interlayer coupling. Results show that the coupled skyrmions reach a stationary regime with a spatial separation due to the opposite gyrovector in the two layers. A transient regime with finite acceleration and limited time response is observed. The phenomenon is quantitatively described using two coupled Thiele equations.
Article
Materials Science, Multidisciplinary
Gao-Wei Qiu, Yi Zhou
Summary: Under the influence of a magnetic field, two weakly linked superconducting ultrathin films exhibit different superconducting states, with one characterized by staggered supercurrent loops and a superfluid density wave, and the other by uniform superfluid density. The phase transition between these two states falls within a specific universality class.
Article
Materials Science, Multidisciplinary
J. C. Bellizotti Souza, N. P. Vizarim, C. J. O. Reichhardt, C. Reichhardt, P. A. Venegas
Summary: By manipulating the amplitude and direction of the ac drive, researchers can control the movement direction and velocity of skyrmions in funnel geometries. When the ac drive is parallel to the funnel axis, skyrmions move in the easy direction at a quantized average velocity, while perpendicular ac drives induce constant velocity movement in the hard direction. Asymmetric biharmonic ac drives can lead to a combination of effects, influencing the skyrmion's motion.
Article
Physics, Applied
Naveen Sisodia, Johan Pelloux-Prayer, Liliana D. Buda-Prejbeanu, Lorena Anghel, Gilles Gaudin, Olivier Boulle
Summary: By utilizing the dynamics of skyrmions interacting with anisotropy energy barriers patterned by ion irradiation, programmable logic gates have been designed to achieve logic gate functionality. These skyrmion logic gates can solely use skyrmions as logic inputs without the need for complex additional devices.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Sigurd Flagan, Daniel Riedel, Alisa Javadi, Tomasz Jakubczyk, Patrick Maletinsky, Richard J. Warburton
Summary: The nitrogen-vacancy (NV) center in diamond, with a highly coherent, optically addressable electron spin, is a promising candidate for a node in a quantum network. A resonant microcavity can enhance the flux of coherent photons emitted from single NV centers. In this study, an open Fabry-Perot microcavity geometry containing a single-crystal diamond membrane is presented, which operates in a regime where the vacuum electric field is strongly confined to the diamond membrane.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Mona Bhukta, Braj Bhusan Singh, Sougata Mallick, Stanislas Rohart, Subhankar Bedanta
Summary: Topological magnetic textures, such as skyrmions and antiskyrmions, are potential candidates for future magnetic logic and memory devices. Recent research has shown the coexistence of skyrmions and antiskyrmions with opposite topological charge in frustrated ferromagnets, which expands the applications of topological charge. In this study, a synthetic antiferromagnetic system is proposed to stabilize and coexist six novel elliptical topological textures.
Article
Physics, Multidisciplinary
Jodok Happacher, David A. Broadway, Juanita Bocquel, Patrick Reiser, Alejandro Jimenez, Marta A. Tschudin, Lucas Thiel, Dominik Rohner, Marcel li Grimau Puigibert, Brendan Shields, Jeronimo R. Maze, Vincent Jacques, Patrick Maletinsky
Summary: We investigate the magnetic field dependent photophysics of individual nitrogen-vacancy (NV) color centers in diamond under cryogenic conditions. At different magnetic fields, we observe significant reductions in the NV photoluminescence rate, indicating a decrease in the optical readout efficiency of the NV's ground state spin. This study provides new insights into the structure of the NVs' excited states and offers a new tool for effective characterization, which can be used to study strain-dependent variations, NV charge state dynamics, and the applicability of NV centers for low-temperature quantum sensing.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Applied
Hai Zhong, Aurore Finco, Johanna Fischer, Angela Haykal, Karim Bouzehouane, Cecile Carretero, Florian Godel, Patrick Maletinsky, Mathieu Munsch, Stephane Fusil, Vincent Jacques, Vincent Garcia
Summary: Scientists have successfully imaged two stable spin cycloids in BiFeO3 epitaxial thin films using a commercial scanning N-V magnetometer. Each ferroelectric domain is coupled to a single spin cycloid, forming a unique magnetic pattern. By manipulating these ferroelectric domains at the local scale using piezoresponse force microscopy, researchers have gained insights into the physical parameters and impact of each spin-cycloid type on the magnetic field.
PHYSICAL REVIEW APPLIED
(2022)
Article
Optics
Sigurd Flagan, Patrick Maletinsky, Richard J. Warburton, Daniel Riedel
Summary: This research demonstrates precise control of the absolute frequency and frequency difference between two resonator modes in Fabry-Perot microcavities by incorporating a diamond micromembrane with a small thickness gradient. The double-resonance enhancement of nonlinear optical processes is achieved by tuning the mirror separation and diamond thickness, allowing for a wide frequency range for pump laser tuning.
Article
Optics
Camilo M. Prada, Luis J. Martinez
Summary: This research investigates the optomechanical effect on a single nano-particle inside an optical cavity through quantum theory, revealing three forces related to gradient force, back-action force from photon energy change, and reactive force from external field-cavity coupling. By studying the dynamical system of a dielectric particle in a small mode volume cavity with a quasi-periodic pattern, valuable insights are gained for controlling various levitated nano-particles through optomechanical coupling.
Article
Physics, Applied
V. Yurgens, A. Corazza, J. A. Zuber, M. Gruet, M. Kasperczyk, B. J. Shields, R. J. Warburton, Y. Fontana, P. Maletinsky
Summary: This study demonstrates that implantation of carbon ions can yield a comparable density of NVs as implantation of nitrogen ions, and it results in NV populations with narrow optical linewidths and low charge-noise levels even in thin diamond microstructures.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Brindaban Ojha, Sougata Mallick, Sujit Panigrahy, Minaxi Sharma, Andre Thiaville, Stanislas Rohart, Subhankar Bedanta
Summary: Magnetic skyrmions are topologically stable spin swirling particles that hold promise for future spintronic devices. The low critical current density required for their motion makes them attractive for energy efficient electronic devices. In this study, the Pt/CoFeB/MgO heterostructures were investigated and skyrmions were successfully stabilized at room temperature. The presence of a low pinning landscape in the samples was confirmed by the distortion of skyrmion shape even under the influence of weak magnetic fields from low moment magnetic tips during magnetic force microscopy (MFM) scans. The threshold current density required to drive the skyrmions in our sample was found to be low, with velocities of few 10 m/s.
Article
Physics, Applied
A. E. E. Dubois, D. A. Broadway, A. Stark, M. A. Tschudin, A. J. Healey, S. D. Huber, J. -P. Tetienne, E. Greplova, P. Maletinsky
Summary: This article introduces a neural-network-based method for solving the inverse problem of inferring the underlying source configuration based on measurement data. The method is efficient and robust in eliminating numerical artifacts, and it significantly improves reconstruction compared to traditional methods. It can be applied to inverse problem solving with different measurement techniques.
PHYSICAL REVIEW APPLIED
(2022)
Article
Quantum Science & Technology
B. Burgler, T. F. Sjolander, O. Brinza, A. Tallaire, J. Achard, P. Maletinsky
Summary: Solid state spins, particularly the Nitrogen-Vacancy (NV) center in diamond, have demonstrated great potential for quantum sensing applications. However, the dominant quantum sensing schemes using microwave or radio-frequency driving have limitations in miniaturization, energy efficiency, and non-invasiveness. In this study, we propose a purely optical approach to coherent quantum sensing using the NV center's N-15 nuclear spin, and demonstrate all-optical free-induction decay measurements on both single spins and spin ensembles. Our results open up possibilities for highly compact quantum sensors in challenging environments.
NPJ QUANTUM INFORMATION
(2023)
Article
Materials Science, Multidisciplinary
Sujit Panigrahy, Sougata Mallick, Joao Sampaio, Stanislas Rohart
Summary: We study the behavior of magnetic skyrmions in synthetic antiferromagnets with interlayer coupling. Results show that the coupled skyrmions reach a stationary regime with a spatial separation due to the opposite gyrovector in the two layers. A transient regime with finite acceleration and limited time response is observed. The phenomenon is quantitatively described using two coupled Thiele equations.
Article
Materials Science, Multidisciplinary
Leo Berges, Eloi Haltz, Sujit Panigrahy, Sougata Mallick, Raphael Weil, Stanislas Rohart, Alexandra Mougin, Joao Sampaio
Summary: This study investigates the characteristics of magnetic skyrmions driven by spin-orbit torques in a low-pinning amorphous material at room temperature. The experimental results show that the velocity of the skyrmions increases linearly with the current, while maintaining a constant deflection angle. By manipulating the external magnetic field, the diameter of the skyrmions can be varied, leading to increased mobility.
