Apr 4 (Tue) @ 2:00pm: "Exploration of Quantum Phenomena in 2D-van der Waals Materials and Devices for Ultra-energy-efficient Computing," Arnab Pal, ECE PhD Defense

Date and Time
Engineering Science Building (ESB), Rm 2001

Zoom Meeting: https://ucsb.zoom.us/j/5311928607


This PhD dissertation explores the potential of two-dimensional (2D) layered materials to revolutionize computing and communication beyond today's electronics. The invention of metal-oxide-semiconductor field-effect-transistor (MOSFET) in the late 1959 has driven the need for dimensional scaling and new applications, making 2D materials with their exotic structural, physical, electrical, and magnetic properties, an attractive solution. I will first present a comprehensive analysis of the various electrical contact topologies to 2D materials, leading to the development of the first comprehensive numerical model for contact resistance, addressing efficient charge injection. This work lays the foundation for the next stage of my research, which involves developing a comprehensive mobility model for quantifying transport in 2D materials to aid the design of high-performance 2D-FETs.

By coupling the electrical charge injection and transport models, I will discuss the results of the first comprehensive scaling analysis of 2D materials in emerging gate-all-around architectures, enabling the design of ultra-energy-efficient and compact transistors for sustaining Moore’s law. Further energy-efficiency gains can be achieved through use of steep-slope 2D-Tunneling Field-Effect-Transistors (2D-TFETs), and I will present the first compact model for such devices. This model is then used to benchmark 2D-TFET device performance in emerging neuromorphic (NM) computing architectures, designed with both neuronal and synaptic functionalities. The simulations promise impressive energy-efficiency gains of close to three orders of magnitude compared to state-of-the-art MOSFETs.

In addition to the conventional charge-based computing methodologies, spin-based computing is another alternative computing platform that offers an additional route for energy-efficient computing. However, there are two major drawbacks to realizing useful spin-based computing devices with 2D-materials, and they are – efficient spin injection, and efficient spin transport. In the next section, therefore, I will talk about the role of contact anisotropies in contacts to 2D-materials for efficient spin injection, and then I will discuss the framework for modeling spin-transport in these materials.

Therefore, by judiciously exploiting and manipulating both the charge- and quantum-information of these devices, significant improvements in energy efficiency beyond what is currently achievable can be realized, leading to a brighter, happier, and safer life.


Arnab Pal is a PhD candidate and Graduate Student Researcher in the Nanoelectronics Research Laboratory (NRL), Department of Electrical and Computer Engineering at University of California, Santa Barbara, advised by Prof. Kaustav Banerjee. His doctoral research is focused on the exploration, analysis and modeling of fundamental physics of charge/spin injection/transport and its applicability in designing energy-efficient high-performance transistors. His doctoral research has been chronicled in 3 first author, and additional 4 co-author, publications in IEEE IEDM, the premier conference in electron devices, and further first author publications in Advanced Materials, MRS Bulletin, and IEEE TED. His research has also been highlighted by Intel, indicating its significance in the field.

Hosted by: Professor Kaustav Banerjee, Nanoelectronics Research Lab

Submitted by: Arnab Pal <arnab@ucsb.edu>