Laura J. Heyderman


Last Name

Heyderman

First Name

Laura J.

ORCID

0000-0003-3843-6611

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03997 - Heyderman, Laura / Heyderman, Laura

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Publications 1 - 10 of 102
  • Time-resolved imaging of three-dimensional nanoscale magnetization dynamics
    Item type: Journal Article
    Donnelly, Claire; Finizio, Simone; Gliga, Sebastian; et al. (2020)
    Nature Nanotechnology
  • Two-dimensional gradients in magnetic properties created with direct-write laser annealing
    Item type: Journal Article
    Riddiford, Lauren J.; Brock, Jeffrey A.; Murawska, Katarzyna; et al. (2025)
    Nature Communications
    Across the fields of magnetism, microelectronics, optics, and others, engineered local variations in material properties can yield groundbreaking functionalities that play a crucial role in enabling future technologies. One-dimensional lateral gradients in material properties give rise to a plethora of new effects in thin-film magnetic systems. However, extending such gradient-induced behaviors to two dimensions has been challenging to realize experimentally. Here, we demonstrate the creation of two-dimensional complex patterns with continuous variations in magnetic anisotropy, interlayer exchange coupling, and ferrimagnetic compensation at the mesoscopic scale in numerous application-relevant magnetic materials. We exploit our engineered gradients in material properties to demonstrate novel magnetic functionalities, including the creation of a spin wave band pass filter and an architecture for passively resetting the position of a magnetic domain wall. Our results highlight the exciting new physics and device applications enabled by two-dimensional gradients in thin film properties.
  • Nanomagnetic encoding of shape-morphing micromachines
    Item type: Journal Article
    Cui, Jizhai; Huang, Tian-Yun; Luo, Zhaochu; et al. (2019)
    Nature
    Shape-morphing systems, which can perform complex tasks through morphological transformations, are of great interest for future applications in minimally invasive medicine, soft robotics, active metamaterials and smart surfaces. With current fabrication methods, shape-morphing configurations have been embedded into structural design by, for example, spatial distribution of heterogeneous materials9, which cannot be altered once fabricated. The systems are therefore restricted to a single type of transformation that is predetermined by their geometry. Here we develop a strategy to encode multiple shape-morphing instructions into a micromachine by programming the magnetic configurations of arrays of single-domain nanomagnets on connected panels. This programming is achieved by applying a specific sequence of magnetic fields to nanomagnets with suitably tailored switching fields, and results in specific shape transformations of the customized micromachines under an applied magnetic field. Using this concept, we have built an assembly of modular units that can be programmed to morph into letters of the alphabet, and we have constructed a microscale ‘bird’ capable of complex behaviours, including ‘flapping’, ‘hovering’, ‘turning’ and ‘side-slipping’. This establishes a route for the creation of future intelligent microsystems that are reconfigurable and reprogrammable in situ, and that can therefore adapt to complex situations.
  • X-ray linear dichroic orientation tomography: reconstruction of nanoscale three-dimensional orientation fields
    Item type: Journal Article
    Apseros, Andreas; Scagnoli, Valerio; Guizar-Sicairos, Manuel; et al. (2025)
    New Journal of Physics
    Properties in crystalline and ordered materials tend to be anisotropic, with their orientation affecting the macroscopic behavior and functionality of materials. The ability to image the orientation of anisotropic material properties in three dimensions (3D) is fundamental for the understanding and functionality-driven development of novel materials. With the development of x-ray linear dichroic orientation tomography (XL-DOT), it is now possible to non-destructively map 3D orientation fields in micrometer-sized samples. In this work, we present the iterative, gradient-based reconstruction algorithm behind XL-DOT that can be used to map orientations based on linear dichroism in 3D. As linear dichroism can be exhibited by a broad spectrum of materials, XL-DOT can be used to map, for example, crystal orientations as well as ferroic alignment, such as ferroelectric and antiferromagnetic order. We demonstrate the robustness of this technique for orientation fields that exhibit smoothly varying and granular configurations, and subsequently identify and discuss optimal geometries for experimental data acquisition and optimal conditions for the reconstruction. We anticipate that this technique will be instrumental in enabling a deeper understanding of the relationship between material structures and their functionality, quantifying, for example, the orientation of charge distributions and magnetic anisotropies at the nanoscale in a wide variety of systems—from functional to energy materials.
  • Stabilising transient ferromagnetic states in nanopatterned FeRh with shape-induced anisotropy
    Item type: Journal Article
    Grimes, Michael; Sazgari, Vahid; Parchenko, Sergii; et al. (2023)
    Journal of Physics D: Applied Physics
    It is well-known that FeRh undergoes an antiferromagnetic to ferromagnetic (FM) phase transition where the high temperature phase is a low coercivity FM material. However, little is known about the effect of lateral confinement on the transition dynamics in FeRh thin films. Here, we pattern FeRh thin films into arrays of nanowires with a large aspect ratio (100:1) and, with ultrafast probing of the magnetic state in an applied magnetic field, we determine the influence of demagnetization fields on the stability of laser induced FM domains. In particular, with pump-probe Kerr measurements, we demonstrate that, when a magnetic field is applied along the nanowire length, the nanowire arrays exhibit an FM phase (>3.0ns) that is longer-lived than that observed for continuous thin films (≈2.0 ns). With electrical measurements, we also show that the transition temperature depends on the relative orientation of the magnetic field. Indeed, when the FeRh film is patterned with sub-μm features, the transition temperature decreases by up to 7 K depending on the field direction at applied magnetic fields of 1 T. The effects of sample heating are explored using finite-element simulations to determine the heat dissipation following laser excitation across a range of FeRh nanowire widths. These simulations confirm that the increased lifetimes of the magnetic-field-aligned FM domains in the nanowire arrays are not due to differences in heat dissipation. This suggests that FM domain growth and relaxation through the ultrafast phase transition in FeRh nanowires is strongly dependent on the shape anisotropy. This knowledge is important for the fine control of the phase transition in patterned FeRh thin films for nanoscale devices.
  • Computational logic with square rings of nanomagnets
    Item type: Journal Article
    Arava, Hanu; Derlet, Peter M.; Vijayakumar, Jaianth; et al. (2018)
    Nanotechnology
  • Dynamic stabilization of nonequilibrium domain configurations in magnetic squares with high amplitude excitations
    Item type: Journal Article
    Stevenson, Stephanie E.; Moutafis, Christoforos; Heldt, Georg; et al. (2013)
    Physical Review B
  • Mesoscopic magnetic systems: From fundamental properties to devices
    Item type: Journal Article
    Heyderman, Laura J.; Grollier, Julie; Marrows, Christopher H.; et al. (2021)
    Applied Physics Letters
  • Magnetic logic driven by electric current
    Item type: Journal Article
    Gambardella, Pietro; Luo, Zhaochu; Heyderman, Laura J. (2021)
    Physics Today
  • Artificial out-of-plane Ising antiferromagnet on the kagome lattice with very small farther-neighbor couplings
    Item type: Journal Article
    Colbois, Jeanne; Hofhuis, Kevin; Luo, Zhaochu; et al. (2021)
    Physical Review B
    Despite their simple formulation, short-range classical antiferromagnetic Ising models on frustrated lattices give rise to exotic phases of matter, in particular, due to their macroscopic ground-state degeneracy. Recent experiments on artificial spin systems comprising arrays of chirally coupled nanomagnets provide a significant strengthening of the nearest-neighbor couplings compared to systems with dipolar-coupled nanomagnets. This opens the way to design artificial spin systems emulating Ising models with nearest-neighbor couplings. In this paper, we compare the results of an extensive investigation with tensor network and Monte Carlo simulations of the nearest- and farther-neighbor (J1-J2-J3||) kagome Ising antiferromagnet with the experimental spin-spin correlations of a kagome lattice of chirally coupled nanomagnets. Even though the ratios between the farther-neighbor couplings and the nearest-neighbor coupling estimated from micromagnetic simulations are much smaller than for dipolar-coupled nanomagnets, we show that they still play an essential role in the selection of the correlations. © 2021 American Physical Society.
Publications 1 - 10 of 102