Research
Overview
We study the transport of heat, charge, and spin in materials through light-matter interactions. Our research aims to gain a fundamental understanding of heat transport mediated by microscopic carriers, and to address the following key questions:
- How can we tailor the time and length scales of the transport of microscopic heat carriers to obtain desired macroscopic properties?
- How can we utilize heat to enhance device operations?
- How can we develop experimental techniques that can lead to important scientific discoveries?
Nanoscale Thermal Transport
We aim to understand the fundamental thermal transport properties of materials and their interfaces. As the characteristic length scales of materials decrease, thermal transport behaviors begin to deviate from the diffusive processes seen at bulk. Our focus is on understanding how microscopic heat carriers, such as phonons, electrons, and magnons, behave at the nanoscale, and how defects and irregularities alter heat transport. Ultimately, we strive to design the behavior of heat carriers through materials engineering to achieve the macroscopic properties needed for advanced applications.
- 2D materials and heterostructures
- High entropy alloys
- Amorphous materials
Thermal management of Devices
As electronic devices become smaller, smarter, and faster, their power density increases while the surface area for heat dissipation decreases, creating significant challenges for thermal management. In close collaboration with industry, we aim to correlate the thermal transport properties of components across different size scales and find a solution to enhance the thermal performance of devices.
- Thermal interface materials
- High thermal conductivity fillers
- Advanced packaging
Thermally-induced Charge & Spin dynamics
Heating in different forms at various time and length scales can induce diverse charge and spin dynamics, offering potentially new mechanisms for device operation at ultrashort time scales with higher energy efficiency. At these times scales, on the order of 10-12 seconds or picoseconds, heat carriers are far from thermal equilibrium. We investigate how this nonequilibrium state evolves over time and space, and how it interacts with charge and spin dynamics.
- Spin generation/transport in chiral materials
Thermal Methodology
We aim to advance thermal metrology that enables important observations of heat transport behaviors. Our focus includes developing thermometers with high sensitivity to temperature, along with improved spatial and temporal resolutions. We also incorporate machine learning in our data analysis to further extract meaning insights from complex datasets.
- Time-domain thermoreflectance
- Time-domain magneto-optic Kerr effect
- Data analysis with machine learning