All Outputs (35)

Simulations of magnetization reversal in FM/AFM bilayers with THz frequency pulses (2023)
Journal Article
Hirst, J., Ruta, S., Jackson, J., & Ostler, T. (2023). Simulations of magnetization reversal in FM/AFM bilayers with THz frequency pulses. Scientific reports, 13(1), Article 12270. https://doi.org/10.1038/s41598-023-39175-6

It is widely known that antiferromagnets (AFMs) display a high frequency response in the terahertz (THz) range, which opens up the possibility for ultrafast control of their magnetization for next generation data storage and processing applications.... Read More about Simulations of magnetization reversal in FM/AFM bilayers with THz frequency pulses.

Three-dimensional topological magnetic monopoles and their interactions in a ferromagnetic meta-lattice (2023)
Journal Article
Rana, A., Liao, C.-T., Iacocca, E., Zou, J., Pham, M., Lu, X., Cating Subramanian, E.-E., Hung Lo, Y., Ryan, S. A., Bevis, C. S., Karl Jr, R. M., Glaid, A. J., Rable, J., Mahale, P., Hirst, J., Ostler, T., Liu, W., O’Leary, C. M., Yu, Y.-S., Bustillo, K., …Miao, J. (2023). Three-dimensional topological magnetic monopoles and their interactions in a ferromagnetic meta-lattice. Nature nanotechnology, 18, 227–232. https://doi.org/10.1038/s41565-022-01311-0

Topological magnetic monopoles (TMMs), also known as hedgehogs or Bloch points, are three-dimensional (3D) nonlocal spin textures that are robust to thermal and quantum fluctuations due to the topology protection1-4. Although TMMs have been observed... Read More about Three-dimensional topological magnetic monopoles and their interactions in a ferromagnetic meta-lattice.

Local Thermoelectric Response from a Single Néel Domain Wall (2022)
Journal Article
Puttock, R., Barton, C., Saugar, E., Klapetek, P., Fernández-Scarioni, A., Freitas, P., Schumacher, H. W., Ostler, T., & Kazakova, O. (2022). Local Thermoelectric Response from a Single Néel Domain Wall. Science Advances, 8(47), https://doi.org/10.1126/sciadv.adc9798

Spatially resolved thermoelectric detection of magnetic systems provides a unique platform for the investigation of spintronic and spin caloritronic effects. Hitherto, these investigations have been resolution limited, confining analysis of the therm... Read More about Local Thermoelectric Response from a Single Néel Domain Wall.

Timescales and contribution of heating and helicity effect in helicity-dependent all-optical switching (2022)
Journal Article
Li, G.-Q., Zheng, X.-Y., Wang, J.-L., Lu, X.-Y., Wu, J., Cai, J.-W., …Xu, Y.-B. (2023). Timescales and contribution of heating and helicity effect in helicity-dependent all-optical switching. Rare Metals, 42(1), 234-243. https://doi.org/10.1007/s12598-022-02117-8

The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity-dependent all-optical switching (HD-AOS), which hinders understanding the magnetization dynamics involved. Here, applying a dual-pump lase... Read More about Timescales and contribution of heating and helicity effect in helicity-dependent all-optical switching.

Energy exchange dependent transient ferromagnetic like state of ultrafast magnetization dynamics (2022)
Journal Article
Gao, S., Liu, D., Zheng, T., Ostler, T., Chantrell, R., & Xu, C. (2022). Energy exchange dependent transient ferromagnetic like state of ultrafast magnetization dynamics. New Journal of Physics, 24(10), Article 103013. https://doi.org/10.1088/1367-2630/ac95ba

The study of laser-induced ultrafast magnetization dynamics is crucial for the development of information recording technology. Due to the complex mechanism, there is still a lack of comprehensive understanding for ultrafast magnetization dynamics. A... Read More about Energy exchange dependent transient ferromagnetic like state of ultrafast magnetization dynamics.

A Temperature Dependent Micromagnetic Model of the Antiferromagnet Mn 2 Au: A Multiscale Approach (2022)
Journal Article
Hirst, J., Atxitia, U., Ruta, S., Jackson, J., Petit, L., & Ostler, T. (2022). A Temperature Dependent Micromagnetic Model of the Antiferromagnet Mn 2 Au: A Multiscale Approach. Physical review B: Condensed matter and materials physics, 106(9), Article 094402. https://doi.org/10.1103/PhysRevB.106.094402

Antiferromagnets (AFMs) are strong candidates for the future spintronic and memory applications largely because of their inherently fast dynamics and lack of stray fields, with Mn2Au being one of the most promising. For the numerical modelling of mag... Read More about A Temperature Dependent Micromagnetic Model of the Antiferromagnet Mn 2 Au: A Multiscale Approach.

Timescales and contribution of heating and helicity effect in helicity-dependent all- optical switching (2022)
Journal Article
Li, G., Zheng, X., Wang, J., Lu, X., Wu, J., Cai, J., …Xu, Y. (in press). Timescales and contribution of heating and helicity effect in helicity-dependent all- optical switching. Rare Metals,

The manipulation of the magnetic direction by using the ultrafast laser pulse is attractive for its great advantages in terms of speed and energy efficiency for information storage applications. However, the heating and helicity effects induced by ci... Read More about Timescales and contribution of heating and helicity effect in helicity-dependent all- optical switching.

Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co (2021)
Journal Article
Jakobs, F., Ostler, T. A., Lambert, C. H., Yang, Y., Salahuddin, S., Wilson, R. B., …Atxitia, U. (2021). Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co. Physical Review B, 103(10), Article 104422. https://doi.org/10.1103/PhysRevB.103.104422

Many questions are still open regarding the physical mechanisms behind the magnetic switching in Gd-Fe-Co alloys by single optical pulses. Phenomenological models suggest a femtosecond scale exchange relaxation between sublattice magnetization as the... Read More about Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co.

Role of element-specific damping in ultrafast, helicity-independent, all-optical switching dynamics in amorphous (Gd,Tb)Co thin films (2021)
Journal Article
Ceballos, A., Pattabi, A., El-Ghazaly, A., Ruta, S., Simon, C. P., Evans, R. F., …Hellman, F. (2021). Role of element-specific damping in ultrafast, helicity-independent, all-optical switching dynamics in amorphous (Gd,Tb)Co thin films. Physical Review B, 103(2), https://doi.org/10.1103/PhysRevB.103.024438

Ultrafast control of the magnetization in ps timescales by fs laser pulses offers an attractive avenue for applications such as fast magnetic devices for logic and memory. However, ultrafast helicity-independent all-optical switching (HI-AOS) of the... Read More about Role of element-specific damping in ultrafast, helicity-independent, all-optical switching dynamics in amorphous (Gd,Tb)Co thin films.

Atomistic study on the pressure dependence of the melting point of NdFe<inf>12</inf> (2020)
Journal Article
Skelland, C., Westmoreland, S. C., Ostler, T., Evans, R. F., Chantrell, R. W., Yano, M., …Hrkac, G. (2020). Atomistic study on the pressure dependence of the melting point of NdFe12. AIP Advances, 10(2), Article 025130. https://doi.org/10.1063/1.5130450

We investigated, using molecular dynamics, how pressure affects the melting point of the recently theorised and epitaxially grown structure NdFe12. We modified Morse potentials using experimental constants and a genetic algorithm code, before running... Read More about Atomistic study on the pressure dependence of the melting point of NdFe<inf>12</inf>.

The Effect of Interstitial Nitrogen Addition on the Structural Properties of Supercells of NdFe<inf>12-x</inf>Ti<inf>x</inf> (2019)
Journal Article
Skelland, C., Ostler, T., Westmoreland, S. C., Evans, R. F., Chantrell, R. W., Yano, M., …Hrkac, G. (2019). The Effect of Interstitial Nitrogen Addition on the Structural Properties of Supercells of NdFe12-xTix. IEEE Transactions on Magnetics, 55(10), 1-5. https://doi.org/10.1109/TMAG.2019.2920214

We investigated the effect of nitrogenation on 3 × 3 × 2 supercell structures of NdFe12-x Tix from x = 0.028 to x = 1.56 (0.2Ti at. % to 12Ti at. %). We used the molecular dynamics and Boltzmann probabilities to permeate titanium into NdFe12-x Tix ac... Read More about The Effect of Interstitial Nitrogen Addition on the Structural Properties of Supercells of NdFe<inf>12-x</inf>Ti<inf>x</inf>.

Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys (2019)
Journal Article
Iacocca, E., Liu, T. M., Reid, A. H., Fu, Z., Ruta, S., Granitzka, P. W., Jal, E., Bonetti, S., Gray, A. X., Graves, C. E., Kukreja, R., Chen, Z., Higley, D. J., Chase, T., Le Guyader, L., Hirsch, K., Ohldag, H., Schlotter, W. F., Dakovski, G. L., Coslovich, G., …Dürr, H. A. (2019). Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys. Nature communications, 10(1), Article 1756. https://doi.org/10.1038/s41467-019-09577-0

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the diffi... Read More about Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys.

Optical receiver with helicity-dependent magnetization reversal (2018)
Journal Article
Azim, Z. A., Ostler, T. A., Xu, C., & Roy, K. (2019). Optical receiver with helicity-dependent magnetization reversal. IEEE Transactions on Magnetics, 55(1), Article 4400206. https://doi.org/10.1109/TMAG.2018.2878008

In this paper, we propose helicity-dependent switching (HDS) of magnetization in Co/Pt for an energy efficient optical receiver. Designing a low-power optical receiver for optical-to-electrical signal conversion has proven to be very challenging. Cur... Read More about Optical receiver with helicity-dependent magnetization reversal.

Ultrafast double magnetization switching in GdFeCo with two picosecond-delayed femtosecond pump pulses (2018)
Journal Article
Atxitia, U., & Ostler, T. A. (2018). Ultrafast double magnetization switching in GdFeCo with two picosecond-delayed femtosecond pump pulses. Applied physics letters, 113(6), Article 062402. https://doi.org/10.1063/1.5044272

The recently discovered thermally induced magnetization switching (TIMS) induced by single femtosecond laser pulses in ferrimagnetic GdFeCo alloys proceeds on the picosecond time-scale. The rate at which data can be changed for use of TIMS in technol... Read More about Ultrafast double magnetization switching in GdFeCo with two picosecond-delayed femtosecond pump pulses.

Roles of heating and helicity in ultrafast all-optical magnetization switching in TbFeCo (2018)
Journal Article
Lu, X., Zou, X., Hinzke, D., Liu, T., Wang, Y., Cheng, T., …Xu, Y. (2018). Roles of heating and helicity in ultrafast all-optical magnetization switching in TbFeCo. Applied physics letters, 113(3), Article 032405. https://doi.org/10.1063/1.5036720

Using the time-resolved magneto-optical Kerr effect method, helicity-dependent all-optical magnetization switching (HD-AOS) is observed in ferrimagnetic TbFeCo films. Our results reveal the individual roles of the thermal and nonthermal effects after... Read More about Roles of heating and helicity in ultrafast all-optical magnetization switching in TbFeCo.

Probability distribution of substituted titanium in RT12 (R = Nd and Sm; T = Fe and Co) Structures (2018)
Journal Article
Skelland, C., Ostler, T., Westmoreland, S. C., Evans, R. F., Chantrell, R. W., Yano, M., …Hrkac, G. (2018). Probability distribution of substituted titanium in RT12 (R = Nd and Sm; T = Fe and Co) Structures. IEEE Transactions on Magnetics, 54(11), Article 2103405. https://doi.org/10.1109/TMAG.2018.2832603

We investigated the atomic fill site probability distributions across supercell structures of RT12-x Ti (R = Nd and Sm; T = Fe and Co). We use a combined molecular dynamics and Boltzmann distribution approach to extrapolate the probability distributi... Read More about Probability distribution of substituted titanium in RT12 (R = Nd and Sm; T = Fe and Co) Structures.

Competition of lattice and spin excitations in the temperature dependence of spin-wave properties (2018)
Journal Article
Di Gennaro, M., Miranda, A. L., Ostler, T. A., Romero, A. H., & Verstraete, M. J. (2018). Competition of lattice and spin excitations in the temperature dependence of spin-wave properties. Physical Review B, 97(21), Article 214417. https://doi.org/10.1103/PhysRevB.97.214417

The interplay of magnons and phonons can induce strong temperature variations in the magnetic exchange interactions, leading to changes in the magnetothermal response. This is a central mechanism in many magnetic phenomena, and in the new field of Sp... Read More about Competition of lattice and spin excitations in the temperature dependence of spin-wave properties.

Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches (2018)
Journal Article
Cuadrado, R., Oroszlány, L., Deák, A., Ostler, T. A., Meo, A., Chepulskii, R. V., …Chantrell, R. W. (2018). Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches. Physical Review Applied, 9(5), Article 054048. https://doi.org/10.1103/PhysRevApplied.9.054048

Fe/MgO-based magnetic tunnel junctions are among the most promising candidates for spintronic devices due to their high thermal stability and high tunneling magnetoresistance. Despite its apparent simplicity, the nature of the interactions between th... Read More about Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches.

A multiscale model of the effect of Ir thickness on the static and dynamic properties of Fe/Ir/Fe films (2018)
Journal Article
Cuadrado, R., Oroszlány, L., Szunyogh, L., Hrkac, G., Chantrell, R. W., & Ostler, T. A. (2018). A multiscale model of the effect of Ir thickness on the static and dynamic properties of Fe/Ir/Fe films. Scientific reports, 8(1), Article 3879. https://doi.org/10.1038/s41598-018-21934-5

The complex magnetic properties of Fe/Ir/Fe sandwiches are studied using a hierarchical multi-scale model. The approach uses first principles calculations and thermodynamic models to reveal the equilibrium spinwave, magnetization and dynamic demagnet... Read More about A multiscale model of the effect of Ir thickness on the static and dynamic properties of Fe/Ir/Fe films.

Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo (2017)
Journal Article
Moreno, R., Ostler, T. A., Chantrell, R. W., & Chubykalo-Fesenko, O. (2017). Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo. Physical Review B, 96(1), Article 014409. https://doi.org/10.1103/PhysRevB.96.014409

We present atomistic spin dynamics modeling of thermally induced magnetization switching (TIMS) of disordered ferrimagnetic TbCo alloys varying the Tb concentration, laser pulse fluence, and its duration. Our results indicate that deterministic TIMS... Read More about Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo.