Yohannes Abate

Assistant Professor, Condensed Matter Experiment

Ph.D. Physics, University of Iowa, Iowa City, 2006

Location:
Office: Peterson Hall 2 (PH2), Room 202

California State University, Long Beach
Department of Physics & Astronomy
1250 Bellflower Blvd.
Long Beach, CA 90840-3901

Phone: (562) 986-4912
Fax: (562) 985-7924
Email: yabate2@csulb.edu

Webpage:: http://www.csulb.edu/~yabate

Research Interest:
Condensed Matter Experiment.

Many new and exciting phenomena occur in nanometer (10^-9m) scale that are of interest for scientists in academia and industrial applications. However, it is difficult to study these phenomena using light since we cannot focus light to such small dimensions using regular optical lenses due to a limitation imposed by diffraction of light. A technique called apertureless near-field scanning optical microscopy (ANSOM) can overcome this limitation and help us to illuminate only a very small region (< 20 nm) so that we can study very small single nano-scale particles and nano-scale properties. The overall scientific objective of my research is the development and as well application of near-field microscopy technique (ANSOM) to a variety of problems such as plasmon-field imaging of metallic nanoparticles and chemically-specific spectroscopic imaging of semiconductors in the visible and THz spectral regimes.

Primary research focus is to study subwavelength-scale structures and dynamics of Surface Plasmon Polaritons (SPPs) on metal and semiconductor surfaces/interfaces. What limits the propagation length of SPPs on metal and semiconductor surfaces? Is there a consistent reproducible statistical trend that relates carrier concentration with SPPs propagation length? A pertureless near-field optical microscopy (ANSOM) with an interferometric detection scheme has a unique capability to map SPP distribution and conduct direct spatial measurements of the SPPs wave vector, propagation length and reflectivity with subwavelength resolution in amplitude and phase.

These research projects will advance our fundamental understanding of nanoscale plasmonics, a novel phenomenon at the nanoscale, the knowledge of which could enable new types of communication and photonic devices. The projects provide an excellent opportunity to graduate and undergraduate students to learn about this exciting field and acquire interdisciplinary skills required for these studies.

Graduate or undergraduate students interested in my research area are encouraged to send me an email.