Undergraduate Research

Summer of 2010

 Summer2010 

The research team included Dassi Shulman, Nina Berg, Kira Joel and Miriam Koolyk.

Dassi worked independently on spin-Hall models with even spin-Chern number. She developed and completed a numerical analysis that clearly indicates that these models display robust extended states in the bulk, even in the presence of strong disorder. In other words, although the edge states of these models are gapped, their bulk properties remain very much the same as for the topological materials with odd spin-Chern number. A scientific paper is in preparation.

Nina, Kira and Miri simulated mechanical harmonic lattices that display topological phonon modes. The topological phonon modes are the mechanical equivalent of the robust edge states seen in the topological insulators. The students solved the equation of motions for these relatively complex lattices and generated real time movies where the manifestation of the topological phonon modes can be witnessed explicitly. The research was published in the following peer reviewed publication:

N. Berg, K. Joel, M. Koolyk and E. Prodan, Topological phonon modes in filamentary structures, Phys. Rev. E 83, 021913 (2011).

Summer of 2009

 Summer2009 

The team included Amy LeVee, Dassi Shulman, Ramona Rahimian and Mordechai Birnbaum.

Amy worked on simulating tunneling transport in molecular devices with semi-conducting leads, more exactly, alkyl chains connected to Si wires. She completed a study on how the tunneling conductance depends on the length of the alkyl chains and on the temperature. She mapped several interesting quantities that influence the conductance. These were first principle simulations and some of the devices contained more than one thousand atoms. A scientific paper was publish in Physical Review B on this subject:

E. Prodan and A. LeVee, Tunneling devices with semi-conducting leads, Phys. Rev. B 81, 085307 (2010).

Ramona and Dassi worked together on what we call the tunneling transistor. The idea is to modify the Fermi level alignment using metallic structure that are hold at different electric potentials. The research is not concluded yet.

Mordy worked on topological materials. He generated the atomic structures of several devices that included complicated topological materials. He completed first principle simulations on these devices in order to better understand their properties.