Boris Kozinsky
Email: bkoz & mit . edu
Office: MIT 13-4066
Phone: (781) 856-5228
Education:
Ph.D. Candidate, Physics Dept, MIT (expected June 2007)
B.S. Physics, B.S. Mathematics, and B.S. Electrical Engineering and Computer Science, MIT (2000)
Research Interest: Electronic properties of low-dimensional systems from ab-initio calculations
Detailed Project Description:
My research lies on the interface of materials science and condensed matter theory and has been focused on applications of first-principles molecular modeling to understanding the physics of electronic interactions in 0D, 1D, and 2D systems, as well as development of more efficient methods of ab-initio simulations of such systems.
Nanotubes have recently surfaced as very promising components of nanoscale systems in a wide range of applications, from nano-electronics to chemical sensing and energy storage. One of major obstacles to progress in this field is the lack of control over the chirality (type) of nanotubes produced during growth. While for boron-nitride nanotubes this is not much of an issue, carbon nanotubes come in many varieties anything from insulator to a ballistic conductor. This universality is also what makes carbon nanotubes so attractive and interesting. Our recent work involved calculating dielectric response of different types of tubes, and our results are relevant to understanding and engineering new ways of separating nanotubes by type and diameter using their different dielectric properties. To understand dielectric properties of nanotubes, one must first examine the electronic correlations in 2D graphene and boron-nitride sheets. Our studies of these two materials reveal very distinct features that explain much of the differences between carbon and boron-nitride nanotubes and allow accurate predictions of the properties of multi-walled nanotubes.
Metallic carbon nanotubes have been recently observed by several experimental groups to exhibit distinctly non-Fermi liquid behavior, even at room temperature. Conductance laws in these 1D metals are very different from those of a normal metal and are believed to be governed by Luttinger liquid physics. This is very important for electronic applications and we are interested in ab-initio predictions of the interaction parameters of the Luttinger liquid model that describes interactions in these systems. Our results agree with recent experiments and the methodology provides a convenient platform for studying and engineering FET type devices that will take into account these exotic effects.
In simulating low-dimensional systems, such as isolated molecules, tubes and membranes within density-functional framework, one must exercise care when using periodic boundary conditions. Interactions with fictitious periodic images contaminates the calculated quantities, particularly with charged, polarized, and very inhomogeneous systems. Using a combination of analytical and numerical methods, we are developing efficient methods of correcting these effects to dramatically reduce the computational cost and improve accuracy. An extension of this work is a method of calculating properties of low-D systems in polar solutions, as well as charged defects in crystals.
Recently we also began investigations into photonic and plasmonic behaviors of arrays of aligned carbon nanotubes as well as the possibility of an optical switch based on a nanotube field-effect transistor.
Recent projects and upcoming publications:
Correlated electron states and transport in triangular arrays, Phys. Rev. B 72, 235331 (2005).
Static dielectric properties of carbon nanotubes from first principles, Phys. Rev. Lett. 96, 166801 (2006).
Dielectric response of low-dimensional carbon and boron-nitride materials from first principles, Phys. Rev. B, coming soon.
Periodic image corrections in simulations of low-dimensional systems, with Ismaila Dabo and Nicholas Singh-Miller, Phys. Rev. B, coming soon.
Luttinger liquid parameters of metallic carbon nanotubes from first principles, in preparation. Preview at APS March meeting '07.
Intensity of Raman radial breathing mode in carbon nanotube from first principles - ongoing work.
Ab-initio calculation of energetics of defects in crystalline solids ongoing work.