Bridging Different Physics: Coupled Electron and thermal transport at the nanometer scale in emerging materials and devices

Interdisciplinary Areas: Data and Engineering Applications, Micro-, Nano-, and Quantum Engineering, Power, Energy, and the Environment

Project Description

Electro-thermal coupled transport across material interfaces is a limiting factor for many emerging material and device applications including nanoelectronic devices, electronics cooling, thermoelectric power generation, and batteries. Current understanding on both electrical interfacial transport and thermal interfacial transport is limited, although theoretical/computational research has addressed isolated challenges. Moreover, treating electron and phonon transports across complex interfaces in a coupled manner has just started, despite their ubiquitous occurrence in nanomaterials. To address these scientific gaps, the goal of this project is to develop multiscale multiphysics simulation tools to predict electron-phonon coupled interfacial transport properties, and then use the knowledge to design interfaces with enhanced performance. The project is built upon Professors Xiulin Ruan and Gerhard Klimeck’s previous works on electron, phonon, and their coupled transport across interfaces. The project will investigate electron transmission, phonon transmission, electron-phonon coupling and nonequilibrium by integrating first principles calculations, Green’s function methods, mismatch models, Boltzmann transport equation, and NEMO5. Semiconductor-semiconductor and semiconductor-metal interfaces promising for electronic, thermal, and battery applications will be investigated in detail. This work will inspire and guide new experiments rather than merely interpreting existing experimental data, and will significantly reduce the time to discover, assess, and develop innovative material interfaces.

Start Date

Spring or Summer 2022

Postdoctoral Qualifications

The candidate is expected to have earned (or will earn in the near future) a PhD degree in Mechanical Engineering, Electrical Engineering, Physics, or other relevant fields. Previous research experience and scientific publications related to first principles calculations, Green’s function methods, and/or molecular dynamics are desired. The candidate should also have excellent communication (writing and speaking) skills.


Xiulin Ruan, Professor, School of Mechanical Engineering. Email:, website:

Gerhard Klimeck, Professor, School of Electrical and Computer Engineering, and Director of the Network for Computational Nanotechnology. Email:, website:


Prabudhya Roy Chowdhury, Jingjing Shi, Tianli Feng and Xiulin Ruan, "Prediction of Bi2Te3-Sb2Te3 Interfacial Conductance and Superlattice Thermal Conductivity Using Molecular Dynamics Simulations," ACS Appl. Mater. Interfaces 13, 4636-4642 (2021).

P.R. Chowdhury, C. Reynolds, A. Garrett, T.L. Feng, S.P. Adiga, and X.L. Ruan, "Machine learning-maximized Anderson localization in random multilayers", Nano Energy 69, 104428 (2020)

T.L. Feng, Y. Zhong, J.J. Shi, and X.L. Ruan, "Unexpected high inelastic phonon transport across solid-solid interface: Modal nonequilibrium molecular dynamics simulations and Landauer analysis," Phys. Rev. B 99, 045301 (2019).

Yuanchen Chu, Jingjing Shi, Kai Miao, Yang Zhong, Prasad Sarangapani, Tim Fisher, Gerhard Klimeck, Xiulin Ruan, Tillmann Kubis, "Thermal boundary resistance predictions with non-equilibrium Green's function and molecular dynamics simulations", Appl. Phys. Lett. 115, 231601 (2019).

Kai Miao, S. Sadasivam, James Charles, Gerhard Klimeck, Timothy Fisher, Tillmann Kubis, "Büttiker probes for dissipative phonon quantum transport in semiconductor" Applied Physics Letters 108, 113107 (2016); doi:10.1063/1.4944329