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OSE Seminar with Dr. Terefe Habteyes on Plasmonic coupling in sub-nanometer separation distances How important is quantum mechanical effect?

Departmental News

Dr. Terefe Habteyes

Posted: January 30, 2019

Date: Thursday, January 31, 2019 

Time:  11:00 AM to Noon

Location: Physics and Astronomy Building, Rm. 190

Map to Physics and Parking Information click on link:

http://physics.unm.edu/findpanda/

ADA Accommodations are available. Please send us an email in advance for any special accommodations.

Speaker:

Dr. Terefe Habteyes

UNM Chemistry and Chemical Biology Department

Abstract:

Localized surface plasmon resonances of metal nanostructures are very attractive optical properties to localize and enhance surface fields to increase light-matter interaction. Local field enhancement that is sufficient for single molecule detection can be obtained by coupling two or more nanostructures in close proximity. According to the prediction of classical electrodynamics, the field enhancement continuously increases with decreasing separation distance to the touching limit. However, when the separation distance is less than 0.5 nm, quantum mechanical effect (electron tunneling) can be important. In this presentation, first the near-field and far-field properties of localized surface plasmon resonances as well as their applications in spectroscopy and photochemistry will be briefly introduced. Then, the transition of plasmonic optical responses from capacitive gap plasmon resonances to tunneling and to direct conductive coupling will be discussed based on recent experimental observations in Habteyes research group.

Biography:

Terefe Habteyes is associate Professor in the Department of Chemistry and Chemical Biology and member of the Center for High Technology Materials at the University of New Mexixo (UNM). He received his BS (1997) and MS (2000) both in Chemistry from Addis Ababa University, and his PhD in Chemistry in 2008 from the University of Arizona. From 2008 to 2012, he worked on the development of near-field scanning optical microscopy as well as on the design, fabrication and characterization of plasmonic materials as a University of California President’s postdoctoral fellow working at UC Berkeley, and the Molecular Foundry, Lawrence Berkeley National Lab, under the supervision of Profs. Leone and Alivisatos. He began his faculty position at UNM in August 2012. His research interests include super-resolution near-field optical imaging, nanoplasmonics, nanophotonics, photochemistry and plasmon enhanced surface spectroscopy. His research is supported by the NSF CAREER award program and the AFOSR.