E3S REU Participants and Projects: 2011
Undergraduate Researcher: Ayana M. Andalcio
Major: Electrical Engineering
Home Institution: Rice University
Research Project: Scheme for Observing Magnetization Dynamics of Nanomagnets with On-Chip Clocking
Faculty Advisor: Prof. Jeffrey Bokor
Postdoc Mentor: Dr. Mohammad T. Alam
Hosting Organization: Electrical Engineering and Computer Sciences Department, UC Berkeley
Project Abstract: A nanowire consisted of a line of antiferromagnetically coupled nanomagnets can produce unexpected metastable states along the wire that affect the value of the output. This error has occurred both experimentally and through simulations. Current optical microscopy can provide an image at one point in time of the nanowire, but cannot show the time evolutions of the switching nanomagnets. A Photoelectron Emission Microscope uses probe x-ray radiation to emit electrons from a sample, allowing a method to establish the magnetic state on the nanomagnets through the electron spin. Nanomagnets propagate data through on-chip clocking by sending a current pulse along a copper wire to produce a magnetic field strong enough to cause the nanomagnets to reach zero magnetization at its peak, and then stabilize to one of the two remnant states after the removal of the magnetic field. Testing different blocks of the experiment design demonstrates that its implementation should work given that the right amplifiers, focusing optics, and circuitry components are found. Project poster
Undergraduate Researcher: Wei Dai
Major: Electrical Engineering
Home Institution: University of California, Riverside
Research Project: LAO-STO Tunnel Junction Structure Modeling
Faculty Advisor: Prof. Ramamoorthy Ramesh
Postdoc Mentor: Dr. Jan Seidel
Hosting Organization: Material Science and Engineering Department, UC Berkeley
Project Abstract: The interface of LaAlO3 and SrTiO3 semiconductors contain property of superconductivity and mobile electron gas. LaAlO3 and SrTiO3 hetero-junction structures were constructed by epitaxially deposition. I-V Measurements were taken across the interface to better understand the structure’s characteristics. The measurements had shown behavior of negative differential resistance at low bias voltage. We investigate this behavior with theoretical quantum tunneling models produce by Mathematica software. We use the program to plot transmission curves of the barriers of our choice. Comparison is made between the theoretical and lab model to identify the possible cause of negative differential resistance. Project poster
Undergraduate Researcher: Duanni Huang
Major: Electrical Engineering
Home Institution: MIT
Research Project: Investigation of Optical Antenna Coupled Nano-Photodiodes
Faculty Advisor: Prof. Ming C. Wu
Graduate Student Mentors: Michael Eggleston, Ryan Going and Amit Lakhani
Hosting Organization: Electrical Engineering and Computer Sciences Department, UC Berkeley
Project Abstract: Nanometer-scale photodiodes coupled with optical antennas are promising candidates for optical interconnect receivers. Two antenna designs, the stacked optical antenna and nanopatch antenna are analyzed and their viability for use as a photodiode is evaluated. The simulation results show that the stacked optical antenna displays poor practicality as a photodiode but the nanopatch design shows an internal efficiency near 50%. Such a nanopatch diode based on InGaAs is fabricated and tested experimentally to evaluate the diode design. Project poster
Undergraduate Researcher: Forrest Laskowski
Major: Chemistry and Computer Science
Home Institution: Carroll College
Research Project: Quality Assurance of Electrostatic MEM Relays – Radiation Hardness
Faculty Advisor: Prof. Tsu-Jae King Liu
Graduate Student Mentor: Rhesa Nathanael
Hosting Organization: Electrical Engineering and Computer Sciences Department, UC Berkeley
Project Abstract: As electrostatic MEM relays have the potential to solve power density issues related to current MOSFET technology, it has become ever more important to examine device reliability. Not only true of applications on earth, MEM devices likely promise to reduce overhead power consumption aboard spacecraft. Thus this paper provides a brief history of radiation hardness in MEM devices. The experimental effects of radiation on device performance are then examined and device degradation is discussed. Finally the efficacy of this technology for industry, in the near future, is gauged. Project poster
Undergraduate Researcher: Stephen Meckler
Major: Chemistry
Home Institution: Penn State University
Research Project: Material Based Exploration of Ferroelectric Negative Capacitance – The Case of PbTiO3
Faculty Advisor: Prof. Sayeef Salahuddin
Graduate Student Mentor: Asif Khan
Hosting Organization: Electrical Engineering and Computer Sciences Department, UC Berkeley
Project Abstract: The potential of ferroelectric (FE) lead titanate (PbTiO3, PTO) as negative capacitance material was investigated. Atomically smooth epitaxial FE PTO-dielectric SrTiO3 bilayer heterostructures were grown using pulsed laser deposition. Structural and electrical characterization of the samples were performed using the state-of-the-art X-ray diffraction techniques and impedance analyzer. Room temperature electrical charactteization reveals that PTO/STO bilayers outperform previously studied crystals by expressing negative capacitance at lower temperatures. The temperature dependence of capacitance was also studied. These results are promising in the future of energy efficient CMOS technologies, where insulating films can be replaced with ferroelectric thin films to achieve operating voltages lower than the classical limit of 60 mv/decade. Project poster