IQIM Postdoctoral and Graduate Student Seminar

Friday April 24, 2020 11:00 AM

Harvesting proximity effect in 2D Ferromagnetic Semiconductor Heterostructures for Spin and Valleytronics

Speaker: Ding Zhong, Faraon Group
Location: Online Event

Abstract: Monolayer transition metal dichalcogenides host easily accessible spin and valley degrees of freedom that can be used to encode and process information. With the advent of van der Waals heterostructures, there are new opportunities to engineer spin and valleytronic devices with more advanced functionalities. In this talk, I will describe a van der Waals heterostructure composed of a monolayer semiconductor, WSe2, and an ultrathin layered ferromagnetic semiconductor, CrI3. The integration of the two materials enables a strong magnetic proximity effect in WSe2 and spin-selective charge transfer from WSe2 to CrI3. By controlling the individual layer magnetization in CrI3 with a magnetic field, we show that the spin-dependent charge transfer between WSe2 and CrI3 is dominated by the interfacial CrI3 layer, while the proximity exchange field is highly sensitive to the layered magnetic structure as a whole. These properties allow us to achieve unprecedented control of WSe2 valley properties in these devices. Moreover, the photoluminescence detection of WSe2 valley pseudospin provides us with a simple yet powerful tool to probe the layer-resolved magnetization dynamics in CrI3.

Attend the talk at: https://caltech.zoom.us/j/97280252054

Talks will also be posted on IQIM's YouTube page https://www.youtube.com/channel/UC5TeDDv2O31r8B47iEUEgNQ

Series IQIM Postdoctoral and Graduate Student Seminar Series

Contact: Marcia Brown at 626-395-4013 marciab@caltech.edu