Department of Physics

Indian Institute Of Technology Madras , Chennai

Single Molecular Electronics: A new paradigm

Speaker : Prof. Ramesh Thamankar, VIT, Vellore

2018-11-26

Abstract :

The technological advancement occurred over last few decades is always related to the advancement in computer and electronic industry. The miniaturisation of electronic devices has been achieved over half a century is explained using G. Moore’s assumption (Moore’s law). Industries have adopted a top-down approach to fabricate intricate electronic circuitry which has resulted in the computers which helped us to solve many difficult problems in recent times. But the question is how far (small) we can go in miniaturisation? Is there a limit? In this talk, I will briefly explain the new paradigm in electronics which deals with single molecules. The device structures in the few nanometers need a new way of looking at the conduction mechanism. I will discuss in detail two techniques which are well established to study the conduction via single molecule or atomic wires. I will explain in detail about one of its kind laboratory to fabricate single molecular logic devices on Si(100):H surface. The fabrication and measurements are done in a custom designed ultra-high vacuum system which contains 2-low temperature scanning tunnelling microscopes (LT-STM) and a very high-resolution scanning electron microscope (UHV-NANOPROBE). I will also introduce the new intramolecular circuit laws which are needed to understand the operating mechanism of the devices at single molecule level. At the nanoscale, the leakage current in electronic device is also a major concern for the physicists and Engineers. One of the reasons for a device failure is the leakage current path through the ultrathin gate oxide used in the fabrication of transistor. I will discuss the current understanding of the breakdown of gate oxide at ultra-thin limit. Our study is based on scanning tunnelling microscopy and have deciphered the real cause of the gate oxide breakdown at nanoscale.

About the speaker:

After completing master’s in physics (M.Sc.) and Materials Engineering (M.Tech.) in India, Ramesh perused his Ph.D. from Institüt für Experimentalphysik, Physics department at Freie Universität Berlin, Germany. Here he studied the relation between the crystallographic structure and magnetism in 3d alloy ultra-thin films. Then moved to University of California, Riverside to work on the spin polarized electron transport via Carbon Nanotube spin valves. Further, while working at Max Planck Institute for Mikrostrukturphysik in Halle, Germany with Prof. J. Kirschner) one of the pioneers in the field of magnetism in low dimensions) established a process to prepare ultra-high density of magnetic nanodots on single crystal metal surfaces. In 2010, Dr. Thamankar moved to Institute of Materials Research and Engineering (IMRE), A*STAR, Singapore and worked as a scientist to establish a laboratory to fabricate and measure the single molecular logic devices on Si(100):H surfaces. Currently, Dr. Thamankar is affiliated to Vellore Institute of Technology where he works as associate professor in physics department of School of Advanced Sciences. His current interests are to understand the defects in new 2-D materials (Beyond Graphene) specifically synthesized with large energy gap and understanding the spin polarized electron transport in biologically important molecules.

Key Speaker Prof. Ramesh Thamankar, VIT, Vellore
Guests None
Place Seminar Room
Start Time 4:00 PM
Finish Time 5:00 PM
External Link None