Calendar of Events

Yongjie Hu, Ph.D., faculty candidate
Battelle/MIT Postdoctoral Fellow
Department of Mechanical Engineering
Massachusetts Institute of Technology

In our everyday devices, about 6% of the primary energy is lost when converted from on form to another during operation. Nanotechnology holds the promise for dramatically improving device performance and energy efficiency. In this talk, I will discuss our efforts in engineering fundamental energy carriers at the nanoscale, in particular, for solid-state energy conversion, high-performance electronics and coherent quantum computation. First, I will present out state energy conversion, high-performance electronics and coherent quantum computation. First, I will present our recently developed hybrid nanostructures engineered to characterize nanoscale thermal transport. I will discuss how we can independently control the heat flow in a rationally designed path and selectively detect the local temperature. Coupling the system with ultrafast optical spectroscopy and modeling, we determine d the mean free path dependent thermal conductivity in different materials. Our approach can serve as generic metrology for high throughput screening of energy materials and as a guidance tool for next-generation energy device design through phonon engineering. Second, I will present a novel material system achieved through bottom-up chemical synthesis and band structure engineering design. I will discuss out work in building high-performance electrons and integrated circuits, where the developed transistors outperformed the state-of-the are MOSFETs and can be also applied for nano-bio interfaces. I will then talk about our development of a highly sensitive charge sensor integrated with coupled quantum dots, and show that we demonstrated full control and detection over charge dynamics, inter-coupling and lifetimes with GHz pulse manipulations. Finally, I will show that we developed the first ling coherent Quantum Bit in Group-IV materials, which encodes information in the smallest energy quanta ñ spin, for next generation of efficient computation. We believe our efforts in developing new functional nanomaterials and structures will lead to advanced energy-conversion and device-operation paradigm in the future.

BIO: Yongjie Hu is currently a postdoctoral scholar in the Mechanical Engineering Department of the Massachusetts Institute of Technology with Professor Gang Chen, focusing on material optimization and device design for thermal transport and solar energy conversion. He obtained his M.A. (2006) and Ph.D. (2010) from Harvard University with a research focus in the areas of nanotechnology, including nanomaterials synthesis, structure characterization, high-performance devices and transport physics under the supervision of Professor Charles M. Lieber. He received his B.S. in physics from University of Science and Technology of China in 2004. Dr. Hu has received several awards, including the Micro & Nano: Heat Transfer Division Award from ASME 92012), Battelle/MIT Fellowship from MIT (2012), Chinaís National Award for Outstanding Students Studying Abroad (2011) and Fieser Fellowship from Harvard University (2004, 2005)

Tuesday, February 19, 2013
3:10 p.m. , 5312 Stevenson Center
Refreshments at 2:45 - 3:00 p.m. in the Student Lounge Olin Hall