ESE Colloquia & Events

Fall 2018

ESE colloquia are held from 11-12:00pm in Towne 337, unless otherwise noted. For all Penn Engineering events, visit the Penn Calendar.

To be added to the ESE Events mailing list (which sends notifications regarding all departmental colloquia, seminars, and events) please email us at ESEevents@seas.upenn.edu.

Roget Howe
Tuesday, September 18th (Joint MEAM/ESE)
Sigma Aldrich Lecture (Singh and ESE Joint Seminar)
Ali Javey, University of California-Berkeley
Professor, Electrical Engineering and Computer Sciences
"2D Semiconductor Electronics: Advances, Challenges, and Opportunities"
2:00pm, Singh Center Glandt Forum
Read the Abstract and Bio

Abstract:Two-dimensional (2-D) semiconductors exhibit excellent device characteristics, as well as novel optical, electrical, and optoelectronic characteristics. In this talk, I will present our recent advancements in defect passivation, contact engineering, surface charge transfer doping, ultrashort transistors, and heterostructure devices of layered chalcogenides. We have develope da defect passivation technique that allows for observation of near-unity quantum yield in monolayer semiconductors. The work presents the viability of monolayers for efficient light emitting devices. Forming Ohmic contacts for both electrons and holes is necessary in order to exploit the performance limits of enabled devices while shedding light on the intrinsic properties of a material system. In this regard, we have developed different strategies, including the use of surface charge transfer doping at the contacts to thin down the Schottky barriers, thereby, enabling efficient injection of electrons or holes. We have been able to show high performance n- and p-FETs with various 2D materials, including the demonstration of a FET with 1nm physical gate length exhibiting near ideal switching characteristics. Additionally, I will discuss the use of layered chalcogenides for various heterostructure device applications, exploiting charge transfer at the van der Waals heterointerfaces.

Bio: Ali Javey received a Ph.D. degree in chemistry from Stanford University in 2005, and was a Junior Fellow of the Harvard Society of Fellows from 2005 to 2006. He then joined the faculty of the University of California at Berkeley where he is currently a professor of Electrical Engineering and Computer Sciences. He is also a faculty scientist at the Lawrence Berkeley National Laboratory where he serves as the program leader of Electronic Materials (E-Mat). He is the co-director of Berkeley Sensor and Actuator Center (BSAC), and Bay Area PV Consortium (BAPVC). He is an associate editor of ACS Nano. Javey's research interests encompass the fields of chemistry, materials science, and electrical engineering. His work focuses on the integration of nanoscale electronic materials for various technological applications, including low power electronics, flexible circuits and sensors, and energy generation and harvesting. He is the recipient of MRS Outstanding Young Investigator Award (2015), Nano Letters Young Investigator Lectureship (2014); UC Berkeley Electrical Engineering Outstanding Teaching Award (2012); APEC Science Prize for Innovation, Research and Education (2011); Netexplorateur of the Year Award (2011); IEEE Nanotechnology Early Career Award (2010); Alfred P. Sloan Fellow (2010); Mohr Davidow Ventures Innovators Award (2010); National Academy of Sciences Award for Initiatives in Research (2009); Technology Review TR35 (2009); SF Early CAREER Award (2008); U.S. Frontiers of Engineering by National Academy of Engineering (2008); and Peter Verhofstadt Fellowship from the Semiconductor Research Corporation (2003).

Tuesday, October 2nd
Jeremy N. Munday, University of Maryland
Associate Professor, Electrical and Computer Engineering, and
The Institute for Research in Electronics and Applied Physics
"Taming Photons: From Nanoscale Devices to Space Propulsion"

Read the Abstract and Bio

Abstract: Photons are remarkable bundles of energy that can be used to perform a variety of tasks. In this talk, I will present our latest research describing how we control photons to create novel devices ranging from near-IR Si detectors and solar energy harvesters to space propulsion technologies based on photon pressure (light sails) and devices that exploit the quantum nature of the vacuum. In the first part of my talk, I will discuss the concept of hot carriers (i.e. charge carriers with excess kinetic energy) and how they can be used to make near-IR imaging detectors. Next, I will demonstrate the concept of electrically controlled optical components and show how we use these devices to create self-powered smart windows for building integration, attitude control devices for light sails, and as a way to modify the optoelectronic response of a semiconductor. Finally, when no photons are present, quantum fluctuations of electromagnetic fields still exist. In the last part of the talk, I will discuss how we can control these fluctuations (sometimes called virtual photons) to create forces and torques on nanoscale objects, exploiting this effect (i.e. the Casimir effect) for fundamental science and technological applications.

Bio: Dr. Jeremy N. Munday is an Associate Professor in the Department of Electrical and Computer Engineering at the University of Maryland, College Park. He received his PhD in Physics from Harvard University and was a postdoctoral scholar at Caltech prior to his appointment at Maryland. His research themes range from quantum electromechanical phenomena (such as the Casimir effect) to fundamental solar energy conversion processes with an emphasis on the optics, photonics, and thermodynamics of such systems. He is a recipient of the DARPA Young Faculty Award (2018), the NSF CAREER Award (2016), the ONR Young Investigator Program Award (2016), the OSA Adolph Lomb Medal (2015), the IEEE Photonics Society Young Investigator Award (2015), the SPIE Early Career Achievement Award (2014), and the NASA Early Career Faculty Space Technology Research Award (2012).

Tuesday, October 16th
Mahdi Soltanolkotabi, University of Southern California
Assistant Professor, Ming Hsieh Department of Electrical Engineering
"From Shallow to Deep: Rigorous Guarantees for Training Neural Networks"

Read the Abstract and Bio

Abstract: Neural network architectures (a.k.a. deep learning) have recently emerged as powerful tools for automatic knowledge extraction from data, leading to major breakthroughs in a multitude of applications. Despite their wide empirical use the mathematical success of these architectures remains a mystery. A major challenge is that training neural networks correspond to extremely high-dimensional and nonconvex optimization problems and it is not clear how to provably solve them to global optimality. While training neural networks is known to be intractable in general, simple local search heuristics are often surprisingly effective at finding global/high quality optima on real or randomly generated data. In this talk I will discuss some results explaining the success of these heuristics. First, I will discuss results characterizing the training landscape of single hidden layer networks demonstrating that when the number of hidden units are sufficiently large then the optimization landscape has favorable properties that guarantees global convergence of (stochastic) gradient descent to a model with zero training error. Second, I introduce a de-biased variant of gradient descent called Centered Gradient Descent (CGD). I will show that unlike gradient descent, CGD enjoys fast convergence guarantees for arbitrarily deep convolutional neural networks with large stride lengths.

Bio: Mahdi Soltanolkotabi is currently an assistant professor in the Ming Hsieh Department of Electrical Engineering at the University of Southern California. Prior to joining USC, he completed his PhD in electrical engineering at Stanford in 2014. He was a postdoctoral researcher in the EECS department at UC Berkeley during the 2014-2015 academic year. Mahdi is a recipient of the 2017 Google faculty research and the 2018 AFOSR young investigator awards. His research focuses on the design and mathematical understanding of computationally efficient algorithms for optimization, high dimensional statistics, artificial intelligence, machine learning, signal processing and computational imaging. A main focus of his research has been on developing and analyzing algorithms for nonconvex optimization, with provable guarantees of convergence to global optima.

  Tuesday, October 30th
Hua Wang, Georgia Tech
Associate Professor, School of Electrical and Computer Engineering
Read the Abstract and Bio

Abstract: TBD.

Tuesday, November 6th
Anthony Ephremides, University of Maryland
Professor, Department of Electrical and Computer Engineering and the Institute for Systems Research
"On "Age" "
Read the Abstract and Bio

Abstract: This talk will introduce and describe the new notion of Age of Information Updates. It is also referred to as Age of Information (AoI). Briefly, this notion summarizes the latency of received messages from time of generation to final reception. Examples include any monitoring system, data collection from censors, processes that evolve in time (like stock market data, object trajectories, etc.), caching systems at network edge, and many others.

The novelty of the concept consists of viewing all the causes of latency in a unified way. The “age” of information at the receiver at time t is defined as the difference between the current time t and the time u(t) which is the time of generation of the most recently received update.

The AoI is a concept, a metric and a tool. In this talk, we will review its evolution over its brief history (it was introduced in 2012) and highlight some of the progress made in its study since. We will conclude by pointing out some of the fundamental issues that arise from its study and that connect signal processing, sampling, information theory, and network control.

Bio: Anthony Ephremides holds the Cynthia Kim Professorship of Information Technology at the Electrical and Computer Engineering Department of the University of Maryland in College Park where he is a Distinguished University Professor and has a joint appointment at the Institute for Systems Research, of which he was among the founding members in 1986. He obtained his PhD in Electrical Engineering from Princeton University in 1971 and has been with the University of Maryland ever since.

He has held various visiting positions at other Institutions (including MIT, UC Berkeley, ETH Zurich, INRIA, etc), and co-founded and co-directed a NASA-funded Center on Satellite and Hybrid Communication Networks in 1991. He has been the President of Pontos, Inc, a consulting firm, since 1980 and has served as President of the IEEE Information Theory Society in 1987 and as a member of the IEEE Board of Directors in 1989 and 1990. He has been the General Chair and/or the Technical Program Chair of several technical conferences (including the IEEE Information Theory Symposium in1991, 2000, and 2011, the IEEE Conference on Decision and Control in 1986, the ACM Mobihoc in 2003, and the IEEE Infocom in 1999). He has served on the Editorial Board of numerous journals and was the Founding Director of the Fairchild Scholars and Doctoral Fellows Program,, a University-Industry Partnership from 1981 to 1985.

He has received the IEEE Donald E. Fink Prize Paper Award in 1991, the first ACM Achievement Award for Contributions to Wireless Networking in 1996, as well as the 2000 Fred W. Ellersick MILCOM Best Paper Award, the IEEE Third Millennium Medal, the 2000 Outstanding Systems Engineering Faculty Award from the Institute for Systems Research, and the Kirwan Faculty Research and Scholarship Prize from the University of Maryland in 2001, and a few other official recognitions of his work. He also received the 2006 Aaron Wyner Award for Exceptional Service and Leadership to the IEEE Information Theory Society.

He is the author of several hundred papers, conference presentations, and patents, and his research interests lie in the areas of Communication Systems and Networks and all related disciplines, such as Information Theory, Control and Optimization, Satellite Systems, Queueing Models, Signal Processing, etc. He is especially interested in Wireless Networks, Energy Efficient Systems, and the new notion of Age of Information.


  Tuesday, November 13th
David Tse, Stanford University
Professor, Department of Electrical Engineering
Read the Abstract and Bio

Abstract: TBD.

  Tuesday, November 20th
Thanksgiving Week (No Seminar)
Read the Abstract and Bio

Abstract: TBD.

  Tuesday, November 27th
Speaker TBD
Read the Abstract and Bio

Abstract: TBD.

  Tuesday, December 4th
Cris Moore, Santa Fe Institute 
Professor, Science Board 
Read the Abstract and Bio

Abstract: TBD.

Tuesday, December 11th
James Buckwalter, UC Santa Barbara
Professor, Electrical and Computer Engineering
"Demanding Dynamic Range: Linearity, Interface Tolerance, and Energy-Efficiency for RF and Millimeter-wave Integrated Circuits and Systems"
Read the Abstract

Abstract: Future wireless systems – often referred to as 5G – will feature wireless services that demand varied trade-offs between data rate, latency, coverage, and power consumption. A long-awaited migration towards millimeter-wave bands has promised high data rates and low latency due to relatively wide bandwidth (up to 2 GHz) in access and backhaul networks. However, a combination of high-order QAM, OFDM, and multiple beams will result in high peak-to-average power ratio (PAPR) signals in the transmitter. High PAPR demands a linear response and generally a reduction in the efficiency of the circuitry. I will present our recent research that has reformulated these efficiency-linearity tradeoffs in millimeter-wave transmitters to improve the dynamic range.

Full-duplex communication could improve the spectral efficiency or channel estimation in MIMO networks. However, full duplex places significant dynamic range requirements on the receiver to tolerate the strong transmitter interference. I will present a proposed multiple access technique that realizes more than 50 dB of signal rejection before the LNA to relax the potential distortion generation in the receiver and realize a full-duplex link without significant power penalties at RF bands.

Finally, I will present a vision for RF photonic receivers to support millimeter-wave MIMO. Silicon photonic devices offer a low-cost platform that might potentially support co-integration of electronic and photonic circuitry. To overcome the spur-free dynamic range issues confronting RF electro-optic conversion, we will briefly review approaches to improve the linearity of silicon photonic modulators.

Bio: James F. Buckwalter is currently a Professor of Electrical and Computer Engineering with UCSB and was the recipient of a 2004 IBM Ph.D. Fellowship, 2007 Defense Advanced Research Projects Agency (DARPA) Young Faculty Award, 2011 NSF CAREER Award, and 2015 IEEE MTT-S Young Engineer Award. He is a senior member of the IEEE and has published more than 150 conference and journal papers on research related to RF, millimeter-wave, and high-speed optoelectronic circuits and systems.