About

Eric Fullerton is the Endowed Chair Professor and Director of UC San Diego's Center for Memory and Recording Research (CMRR). He is a Distinguished Professor in the departments of Electrical and Computer Engineering and NanoEngineering at UCSD's Jacobs School of Engineering. His research is centered on the engineering of thin film nano-structured materials and devices and the characterization of their structural, magnetic, optical, and transport properties. The particular focus of his research is on magnetic materials, thin films, and devices, but he also explores optical, thermal, superconducting, and ionic responses of nanomaterials. Before joining UCSD in January 2007, Fullerton was a senior manager and research staff member in the Fundamentals of Nano-structured Materials Group at Hitachi Global Storage Technologies (formerly IBM Almaden Research Center). He is a Fellow of the American Physical Society and IEEE and is a member of the National Academy of Engineering. His notable awards include the IBM Outstanding Achievement Award, Docteur Honoris Causa from Université Henri Poincaré, the American Institute of Physics (AIP) Prize for Industrial Applications of Physics, and the IEEE Magnetics Society Achievement Award. He earned his Ph.D. at UCSD in 1991.

Research topics

• Quantum mechanics
• Physics
• Computer Science
• Optoelectronics
• Materials science
• Electrical engineering
• Nanotechnology
• Artificial Intelligence
• Condensed matter physics
• Engineering
• Chemistry
• Optics
• Engineering physics
• Geometry
• Mathematics
• Metallurgy
• Chemical engineering
• Composite material

Selected publications

• Resistive Switching of Spinel Li₄Ti₅O₁₂ Lithium-Ion Battery Material for Neuromorphic Computing

  ACS Applied Engineering Materials · 2025-07-21 · 1 citations

  articleCorresponding

  The rapid rise of AI has exposed significant limitations in conventional Von Neumann computing architecture, particularly in regard to speed and energy efficiency. To address these challenges, researchers are exploring a brain-inspired neuromorphic architecture that mimics biological neural networks, enabling massive parallel processing with reduced power consumption for complex AI computational demands. Recent interest has focused on utilizing battery electrodes and solid electrolyte materials for their resistive switching properties in developing a neuromorphic architecture. These properties are precisely tuned through local- and bulk-level chemical composition modifications via voltage bias stimuli. In this study, we demonstrate fabricating a three-terminal lithium-ion electrochemical transistor based on lithium titanium oxide (Li4Ti5O12), a popular lithium-ion battery anode material. We deposited and characterized LTO thin films using RF sputtering, demonstrating a 6 orders of magnitude increase in electronic conductivity upon lithiation, with conductivity plateauing after 20% lithiation. Density functional theory calculations revealed transformation from the insulating to conducting state, supported by experimental characterization through X-Ray Photoelectron Spectroscopy (XPS) and Direct Current (DC) polarization analyses. The fabricated transistor consisted of LTO as the channel layer, gold as source/drain terminals, lithium phosphorus oxynitride (LiPON) as the lithium-ion conductor, and copper as the gate terminal. The device exhibited clear hysteresis in transfer characteristics due to lithium insertion/extraction processes. Long-term potentiation (LTP) and long-term depression (LTD) measurements showed an asymmetric ratio of 1.425 and maximum/minimum conductance ratio of 7.83. When implemented in a deep neural network (DNN) for MNIST handwritten digit recognition, the device achieved 92.03% accuracy over 20 training epochs. Detailed transport mechanism analysis revealed the crucial role of oxygen vacancies and interface effects in device operation. Our preliminary findings establish LTO-based lithium-ion electrochemical transistors as promising candidates for energy-efficient neuromorphic computing applications, offering potential solutions to traditional Von Neumann architecture limitations.

  PublisherDOI

• Investigation of Dipole-Stabilized Skyrmions in Amorphous Centrosymmetric FeGdPt Multilayers using 4D-STEM

  Microscopy and Microanalysis · 2025-07-01

  articleOpen access
  PublisherOA PDFDOI

• Real space imaging of dipole-stabilized hybrid skyrmions in magnetic multilayer thin films

  Physical review. B./Physical review. B · 2025-09-08

  article

  Magnetic skyrmions are chiral spin textures whose nontrivial topology protects them from annihilation and are a prime candidate for logical bits in future spintronics devices and next-generation magnetic memories. While their topology and structure are typically described in two dimensions, recent works have focused on further understanding their three-dimensional (3D) structure. Specifically, in multilayer thin films, skyrmions stabilized by dipolar fields are expected to exhibit domain walls that are Bloch-type in the center of the film and twist to N\'eel-type towards the surfaces due to stray-field interactions, resulting in a hybrid structure. The thickness-dependent helicity underpins their exceptional stability and is predicted to strongly affect the skyrmions' response to external forces and underlying topology. In this paper, we combine Lorentz transmission electron microscopy and scanning electron microscopy with polarization analysis to image in real space the 3D structure of hybrid skyrmions. We compare our measurements against micromagnetic simulations, which reveal the full hybrid structure, including the depth dependence of core diameter, domain wall width, and skyrmion helicity.

  PublisherDOI

• STEM Ptychographic Holography of Electric and Magnetic Potentials

  Microscopy and Microanalysis · 2025-07-01

  article
  PublisherDOI

• Wavelength Scale All-Optical Magnetization Control in Ferromagnetic Films

  2025-01-01

  article

  We report the first demonstration of tightly focused femtosecond (fs) circularly polarized Bessel-Gauss beams for wavelength-scale magnetization switching in Pt/Co films. When compared to traditional Gaussian beams, these beams show better focusing and energy efficiency.

  PublisherDOI

• Multimodal correlative study of Hall transport and magnetic phases in Fe/Gd multilayer systems

  Applied Physics Letters · 2025-04-01

  article

  The Fe/Gd multilayer system hosts a number of magnetic phases, such as stripe, mixed stripe and skyrmion, skyrmion lattice, and isolated skyrmions for a wide range of temperature and magnetic field. We report different Hall transport signals in a Fe/Gd system through multimodal correlative resonant soft x-ray scattering (RSXS), Hall effect, magneto-optic Kerr effect, and transmission x-ray microscopy measurements. The simultaneous nature of the RSXS and Hall transport measurements allowed us to accurately connect various features in the transport data with the specific magnetic phases. We found that the topological Hall effect (THE) shows peaks with opposite signs, which we attribute to two different mechanisms. Our multimodal correlative study indicates that the sign reversal in THE occurs when the system transforms to and from a skyrmion lattice and low density isolated skyrmion phases. We propose that the skyrmion lattice contributes to the THE through a Berry phase induced emergent magnetic field mechanism in one case, and a skew scattering mechanism corresponding to the isolated low density skyrmion state.

  PublisherDOI

• Ultrafast emergence of ferromagnetism in antiferromagnetic FeRh in high magnetic fields

  npj Spintronics · 2025-02-03 · 5 citations

  articleOpen access

  Ultrafast heating of FeRh by a femtosecond laser pulse launches a magneto-structural phase transition from an antiferromagnetic to a ferromagnetic state. Aiming to reveal the ultrafast kinetics of this transition, we studied magnetization dynamics with the help of the magneto-optical Kerr effect in a broad range of temperatures (from 4 K to 400 K) and magnetic fields (up to 25 T). Three different types of ultrafast magnetization dynamics were observed and, using a numerically calculated H-T phase diagram, the differences were explained by different initial states of FeRh corresponding to a (i) collinear antiferromagnetic, (ii) canted antiferromagnetic and (iii) ferromagnetic alignment of spins. We argue that ultrafast heating of FeRh in the canted antiferromagnetic phase launches practically the fastest possible emergence of ferromagnetism in this material. The magnetization emerges on a time scale of 2 ps, which corresponds to the earlier reported time scale of the structural changes during the phase transition.

  PublisherOA PDFDOI

• Distinct element-specific nanoscale magnetization dynamics following ultrafast laser excitation

  ArXiv.org · 2025-06-26

  preprintOpen access

  Time-resolved ultrafast extreme ultraviolet (EUV) magnetic scattering is used to study laser-driven ultrafast magnetization dynamics of labyrinthine domains in a [Co/Ni/Pt] multilayer. Our measurements at the Co and Ni M-edges reveal distinct ultrafast distortions of the scattering pattern position and width for Ni compared to Co. Ni shows a strong modification of the scattering pattern, approximately 10 to 40 times stronger than Co. As distortions of the labyrinthine pattern in reciprocal space relate to the modification of domain textures in real space, significant differences in Co and Ni highlight a 3D distortion of the domain pattern in the far-from-equilibrium regime.

  PublisherOA PDFDOI

• Effects of annealing on coercivity, switching mechanisms, and structural characteristics of Co/Pd multilayer for magnetic memory

  Journal of Applied Physics · 2025-05-21 · 3 citations

  articleOpen access

  This study investigates the effects of annealing on the magnetic and structural properties of Co/Pd multilayers, which are promising candidates for perpendicular magnetic tunnel junctions, critical to magneto-resistive random-access memory (MRAM) applications. Co/Pd multilayers with various bilayer counts (5, 10, 15, and 20) were synthesized via DC magnetron sputtering and subjected to annealing at temperatures ranging from 250 to 450 °C. Magnetic measurements, including standard magnetization-vs-field major hysteresis loops and first-order reversal curve analysis, showed that annealing increased coercivity, reaching a maximum of 5100 Oe at 450 °C for 20 bilayers. Magneto-Optical Kerr Effect imaging confirmed domain-wall motion as the switching mechanism, except in the highest temperature annealed samples, which appear to behave more like independent particles. Structural characterization using x-ray diffraction revealed enhanced crystallinity with annealing, indicating improved atomic ordering. Atomic force microscopy demonstrated increased surface roughness with bilayer count due to increased thickness. These results show that Co/Pd-based multilayers are tolerant of high-temperature processing, as required for CMOS-based MRAM.

  PublisherDOI

• Temperature Dependent Spin Dynamics in La_0.67Sr_0.33MnO₃/Pt Bilayers

  Advanced Materials Interfaces · 2025-04-04 · 1 citations

  articleOpen access

  Abstract Complex ferromagnetic oxides such as La 0.67 Sr 0.33 MnO 3 (LSMO) offer pathways for creating energy‐efficient spintronic devices with new functionalities. LSMO exhibits high‐temperature ferromagnetism, half metallicity, sharp resonance linewidth, low damping, and a large anisotropic magnetoresistance response. Combined with Pt, a proven material with high spin‐charge conversion efficiency, LSMO can be used to create robust nano‐oscillators for neuromorphic computing. Ferromagnetic resonance (FMR) and device‐level spin‐pumping FMR measurements are performed to investigate the magnetization dynamics and spin transport in NdGaO 3 (110)/LSMO(15 nm)/Pt(0 and 5 nm) thin films ranging from 300 K to 90 K and compare the device performance with Py(7 nm)/Pt(5 nm) sample. The spin current pumped into Pt is quantified to determine the temperature‐dependent influence of interfacial interactions. The generated spin current in the micro‐device is maximum at 170 K for the optimally grown LSMO/Pt films. Additionally, this bilayer system exhibits low magnetic Gilbert damping (0.002), small linewidth (12 Oe), and a large spin Hall angle (≈3.2%) at 170 K. Ex situ deposited LSMO/Pt bilayers demonstrate excellent dynamic response, exhibiting fourfold enhancement in signal output, eightfold reduction in damping, and a threefold reduction in linewidth as compared to the Pt/Py system. Such robust device‐level performance can pave way for energy‐efficient spintronic‐based devices.

  PublisherOA PDFDOI

Recent grants

• Materials World Network: Novel Magnetic Materials for Spin-Torque Physics and Devices.

  NSF · $330k · 2010–2013

• Materials World Network: New Functionality in Complex Magnetic Structures with Perpendicular Anisotropy

  NSF · $450k · 2013–2016

• Strain-induced modification of nanoscale materials properties

  NSF · $640k · 2014–2018

• Collaborative Research: Engineering, imaging and control of three-dimensional topological magnetic materials

  NSF · $413k · 2021–2024

• Electrical control of nanoscale magnetic devices.

  NSF · $360k · 2010–2013

Frequent coauthors

• S. Mangin

  200 shared

• Sergio Montoya

  University of California, San Diego

  102 shared

• Rajasekhar Medapalli

  82 shared

• Olav Hellwig

  Helmholtz-Zentrum Dresden-Rossendorf

  79 shared

• Matteo Gatti

  Commissariat à l'Énergie Atomique et aux Énergies Alternatives

  69 shared

• S. D. Kevan

  Lawrence Berkeley National Laboratory

  66 shared

• Sheena K. K. Patel

  University of California, San Diego

  65 shared

• M. Hehn

  Université de Lorraine

  61 shared

Education

• Ph.D.

  University of California, San Diego

  1991

Awards & honors

• IBM Outstanding Achievement Award
• Docteur Honoris Causa from Université Henri Poincaré
• American Institute of Physics (AIP) Prize for Industrial App…
• IEEE Magnetics Society Achievement Award
• Fellow of the American Physical Society