< BK21+ BEST Seminar Series Announcement> 

Time and Date : 16:00 ~ 17:00 Friday 06/01/2018

Place : B041, Engineering Building #2

Title : Quantum Transport in Graphene Heterostructures

Abstract:

The nanoelectronics industry is facing exciting challenges as the limits of silicon are being reached. The post-CMOS era demands (1) energy-efficient and higher capacity memory, (2) light-weight, low-power, small application-specific devices, and (3) unprecedented super computers for computationally infeasible problems. Bringing new materials, structures, and physics would be the way of addressing such various demands. Graphene is one of promising electron systems for exotic electron physics and diverse potential device applications. In this talk, I will present a comprehensive study of electron transport in bilayer graphene and its heterostructures, which may serve as a platform for novel transistors. The talk will introduce a non-local direct chemical potential measurement technique using double bilayer graphene heterostructures, which consist of two parallel bilayer graphene separated by a hexagonal boron nitride dielectric. The measured chemical potential vs density characteristics, containing signatures of electron-electron interactions and electron-hole asymmetry will be addressed. The talk will then discuss quantum Hall (QH) effect in bilayer graphene, presenting spin-to-valley polarized phase transitions, interaction-driven negative compressibility, and novel QH phases, which are predicted to possess a coherent superposition of two different electronic states. Gate-tunable resonant tunneling and negative differential resistance in the interlayer current vs voltage characteristics will be also presented. Lastly, I will discuss plasmonic applications as well using two-dimensional materials, mediated by the studies in electron transport and band alignment in graphene heterostructures.

Presenter: Prof. Kayoung Lee / Department of Materials Science and Engineering, GIST 

Host: Prof. Taeyoon Lee, Yonsei EEE