Event
MSE Seminar: Dr. Brandi Wooten, U.S. Army DEVCOM
Wednesday, November 18, 2026
3:30 p.m.
Room 2108 Chemical and Nuclear Engineering Building
Sherri Tatum
301-405-5240
statum12@umd.edu
From Concept to Quasiparticle: A Research Journey in Ferroelectric Thermal Transport
Abstract: Solid-state solutions often drive major progress in technological and industrial systems, as demonstrated by the transistor, photovoltaics, and magnetic memory. Such transformative breakthroughs often originate in fundamental research efforts focused on the underlying physics of functional materials. Within this context, we seek to investigate the coupling of lattice vibrations (phonons) and polarization in ferroelectric (FE) materials. Ferrons - thermal perturbations of ferroelectric order - were first theorized in 2021 (Bauer et al., PRL 126 (2021)). They are defined as a subset of acoustic phonons that couple to optical modes through piezoelectric strain, allowing them to carry both heat and polarization. Analogous to magnons, the quanta of spin waves in ferromagnetic materials, ferrons are expected to behave similarly such as contributing to the system’s thermal conductivity, thermal diffusivity, Peltier response and drag-mediated transport. The first indirect experimental evidence of these new quasiparticles, published in 2023, demonstrated a small change in the thermal conductivity, thermal diffusivity and sound velocity under an applied electric field in a polycrystalline lead zirconium titanate actuator (Wooten et al., Sci. Adv. 9 (2023)). These results agreed well with calculations using the material’s piezoelectric coefficients (a measurement of lattice strain under an applied field) and Grüneisen parameter (quantifying the anharmonicity of the phonon modes).
With the goal of completing the Onsager reciprocal relations for polarization caloritronics, I will present our latest results for the polarization Peltier effect in Pb(Mg,Nb)O3-PbTiO3 (PMN-PT) and ferron-drag thermopower in heterostructures with a PMN-PT substrate. Additionally, I will share my research journey and describe how a chance encounter with an intriguing concept developed from an initial exploration into a full research proposal investigating the properties of this novel quasiparticle. Further, I will reflect on witnessing the emergence of the brand-new field of polarization caloritronics and its growth into an international research effort, with groups from diverse backgrounds pursuing complementary approaches to advance the collective knowledge base.
Bio: Brandi Wooten is a research materials scientist in the advanced electronics branch at the Army Research Lab (ARL) in Adelphi, MD. She completed her PhD in materials science with a focus on thermal, magnetic and ferroelectric materials at Ohio State University under the advisement of Prof. Joseph P. Heremans in 2023. There, she was awarded the Pat Tillman scholarship for scholarly merit and her Army veteran service, as well as the DoD Science, Mathematics, and Research for Transformation (SMART) Scholarship. At ARL during phase two of the SMART program, she received the innovation award seed grant which funds her continued studies into ferron physics. Her other research priorities include testing ferroelectric FETs for neuromorphic computing applications and investigating ferromagnetic and topological material systems for polarization sensing.
