Understanding heat transport at the nanometer scale is critical for semiconductor devices, quantum materials, and thermal management of nanostructures, yet direct local measurements of thermal conductivity and heat capacity remain scarce. We developed a laser-excitation system integrated into a scanning transmission electron microscope (STEM) for nanoscale thermal transport measurements using ultra-high-resolution electron energy-loss spectroscopy (EELS). A fiber-coupled laser is introduced via a modified aperture mechanism, enabling flexible holder geometries and large tilt angles without optical elements in the polepiece gap. Synchronization of pulsed laser excitation with an externally gated direct electron detector provides temporal resolution about 50 ns at <10 meV energy resolution. Local temperatures are determined via the principle of detailed balance, and thermal transport parameters are extracted by fitting a forward-time central-space heat diffusion model including radiative losses. For amorphous carbon films, we obtain a thermal conductivity of 1.24 m⋅KW and a heat capacity of 821 kg⋅KJ, consistent with literature. This framework enables time-resolved nanoscale measurements of thermal transport in materials and devices.
@article{arxiv.2602.05911,
title = {Platform and Framework for Time-Resolved Nanoscale Thermal Transport Measurements in STEM},
author = {Mairi McCauley and Joel Martis and Ondrej L. Krivanek and Ben Plotkin-Swing and Andreas Mittelberger and Tolga Wagner and Hüseyin Çelik and Grigory Kornilov and Meng Zhao and Matthias Meffert and Luca Piazza and Tracy C. Lovejoy and Guillaume Radtke and Christoph Koch and Benedikt Haas},
journal= {arXiv preprint arXiv:2602.05911},
year = {2026}
}