ECE Electronics & Photonics researchers receive a Department of Energy (DOE) grant for $4.4 million

January 5th, 2018

illustration of a city with data movement Grant is to develop integrated photonics technology that will make it possible to incorporate photonics right onto the switch chip, eliminating the need for comparatively inefficient copper wiring

Whenever you go onto your Facebook or LinkedIn page, banks of servers at enormous kilometer-long data centers that make up the cloud spring into action, gathering data. The various types of data live on different servers, so a tremendous amount of communication takes place between servers to assemble the package you’re presented as a user. Providing that service to billions of users requires many millions of servers and a great deal of energy.

Not surprisingly, Facebook and other digital giants are always looking for faster and more-efficient ways to store, fetch, and distribute all that data, which, for much of its journey, moves at the speed of light via fiber-optic cable. But there are bottlenecks in the data-storage-and-retrieval system created by copper-wired switches that link servers to each other and to the fiber-optic system. All that copper creates inefficiencies — which in turn produce heat, which requires more electricity to remove — that waste energy and slow the speed of data transmission.

The team projects at least a 90-percent reduction in network power usage in both small- and large-scale systems, and a 200- to 600-percent increase in the overall efficiency of data-center transactions.

The team includes principal investigator Clint Schow and fellow electrical and computer engineering faculty members and co-PI’s Adel Saleh, Jim Buckwalter, Jonathan Klamkin, and Larry Coldren, plus about a dozen graduate students and postdoctoral researchers.

"Switching Up" – Convergence: The Magazine of Engineering and the Sciences at UCSB (Issue 20, Fall 2017)

Schow's COE Profile

ECE Electronics & Photonics Research

Unite to Light, the nonprofit founded by ECE Prof. John Bowers, featured in The UCSB Current article “Guiding Light”

December 20th, 2017

unite to light logo
Unite to Light to ship 9,000 solar lights to Bangladesh for Rohingya refugees – the distribution effort with RTM International, a Bangladesh-based NGO, and the United Nations Population Fund (UNFPA) will prioritize midwives, pregnant women and new mothers

“Unite to Light is very fortunate to work with our partner organizations to send lights to those who need them the most,” said Bowers, who holds the Fred Kavli Chair in Nanotechnology — and who also created the solar-powered LED devices. “They have the connections on the ground to ensure that the lights reach those who really need them.”

RTM purchased the first 8,000 solar lights for the Rohingya refugees in Bangladesh. Unite to Light itself is donating an additional 1,000 through its “buy one, give one” program, and direct donations.

“Unite to Light is focused on getting light to those who could not otherwise afford it: children learning to read and study after dark, midwives and health clinics and disaster response,” said Megan Birney, executive director of Unite to Light. “Supplying solar lights to midwives, refugees and new mothers falls squarely into our mission of providing tools for those in need so that they may have a better opportunity to survive and thrive.”

By all accounts, this particular tool is most welcome and deeply appreciated. On receiving a Clean Delivery Kit — solar light included — after a prenatal checkup at a camp-based health facility, Sabekun told a midwife, “I felt so afraid and uncertain this morning, but now I feel more at peace. I feel reassured, I’m glad I came.”

By the close of 2017, Unite to Light in total will have shipped 21,000 solar lamps this year. The organization since its founding in 2011 has distributed over 90,000 lights to 65 countries, including Ghana, South Africa, Haiti and Peru.

The UCSB Current – "Guiding Light" (full article)

Unite to Light

Bowers' COE Profile

ECE Professor Dan Blumenthal named a 2017 National Academy of Inventors (NAI) Fellow

December 13th, 2017

photo of Dan Blumenthal
Blumenthal cited for “demonstrating a highly prolific spirit of innovation in creating or facilitating outstanding inventions that have made a tangible impact on quality of life, economic development and the welfare of society.”

“Our campus is thrilled for Professor Blumenthal on his election to the National Academy of Inventors, a proud and prestigious peer recognition of his creativity in engineering,” said UCSB Chancellor Henry T. Yang. “While celebrating his commitment to innovation, this honor also acknowledges Professor Blumenthal’s important contributions to society through the creative application of his research at the frontier of technology.”

Blumenthal’s UCSB lab develops new hardware and communications technologies to solve complex communications, transmission, switching and signal processing problems out of reach with today’s technologies. Its primary research undertaking is to develop new functions integrated on small chips called photonic circuits and use them to build networks in ways that save energy and increase the scale of connectivity and bandwidth of data centers and the internet.

“It is a great honor to be nominated as a fellow of the NAI and recognized for work that has come to fruition over so many years through working with so many collaborators,” said Blumenthal, head of the ECE’s Optical Communications and Photonic Integration Group and director of UCSB’s Terabit Optical Ethernet Center. “The challenge of combining creativity and engineering to operate on the edge of technology innovation is in itself hugely satisfying. Seeing this technology take root and positively impact generations of fiber communications networks that people use in their everyday lives to be more energy efficient and communicate, conduct business and solve some of today’s toughest problems — as well as train future engineers and create jobs — continues to motivate my desire to innovate and make positive impacts on society.”

Blumenthal holds 3 degrees in EE: a B.S. from the U. of Rochester, an M.S. from Columbia and a doctorate from the U. of Colorado Boulder. He is a fellow of the IEEE and of the Optical Society. He received a Presidential Early Career Award for Scientists and Engineers from the White House in 1999, a National Science Foundation Young Investigator Award in 1994 and an Office of Naval Research Young Investigator Program Award in 1997. Blumenthal has authored or co-authored more than 410 papers, holds 22 patents and is co-author of “Tunable Laser Diodes and Related Optical Sources” (New York: IEEE–Wiley, 2005).

This year’s class of NAI fellows will be inducted during the seventh annual NAI Conference to be held in April in Washington, D.C. Andrew H. Hirshfeld, U.S. commissioner for patents, will provide the keynote address for the induction ceremony.

The UCSB Current – "The Spirit of Innovation" (full article)

Blumenthal's COE Profile

Blumenthal's Lab – Optical Communications and Photonic Integration Group (OCPI)

ECE Professors Li-C. Wang and Clint Schow named 2018 Fellows of the Institute of Electrical and Electronics Engineers (IEEE)

December 13th, 2017

photos of schow and wang
COE’s Schow, Wang and Giovanni Vigna (CS) selected by IEEE for their extraordinary accomplishments in their respective fields

“Ensuring the integrity of computer chips and circuits, using opto-electronic technology to move more data faster and with greater efficiency, and securing computer systems against cybercrime are critical pursuits in the digital age — professors Wang, Schow and Vigna are playing key roles in these important areas,” said Rod Alferness, dean of the UCSB College of Engineering. “We offer congratulations to each of them for receiving this high honor.”

Li-C. Wang

A professor of electrical and computer engineering, Wang is an expert in computer engineering as well as electronic design automation and test, in which intelligent software tools are used to automate the processes of hardware design and verification. Modern hardware design can comprise billions of devices and integrate heterogeneous components that perform a variety of functions, involving complex algorithms and architectures in which their performance and properties must be thoroughly verified and tested to ensure product quality, reliability and safety.

Wang is a recipient of numerous honors and awards, including seven best paper awards presented at leading international conferences, and the Technical Excellence Award for his research contributions to member companies of Semiconductor Research Corporation. He was cited by IEEE for “contributions to statistical timing analysis for integrated circuits,” where his research pioneers the use of statistical data analytics to verify design timing assumptions with silicon measurement data.

This innovative methodology, also called design-silicon timing correlation, later became the foundation for developing other data mining-based methodologies in a variety of design automation and test applications such as functional verification, yield improvement and quality assurance.

Clint Schow

For rapid movement of ever-increasing amounts of data, engineers have turned to photonics, which uses light to transmit information at, well, the speed of light. Light is ideal for efficiently transmitting large amounts of information over long distances (think: fiberoptic cables), but within the confines of computers and other data devices, light becomes a challenge to manipulate.

Schow, also a professor of electrical and computer engineering, focuses his research on integrating photonics and electronics, developing hardware that can translate the information between photon and electron, between optical fiber and wire. He was cited by IEEE for “contributions to high-bandwidth optical interconnects,” which will accelerate the development of higher-performance computers and data centers that can accommodate the growing flood of data. Schow also is a fellow of the Optical Society of America.

IEEE is the world’s largest technical professional organization dedicated to advancing technology for the benefit of humanity through its more than 423,000 members in over 160 countries, and its highly cited publications, conferences, technology standards and professional and educational activities.

Institute of Electrical and Electronics Engineers (IEEE) Fellow Program

The UCSB Current – "High Honors" (full article)

Wang's COE Profile

Schow's COE Profile

ECE graduate student Bowen Song receives the Asia Communications and Photonics Conference (ACP) Best Student Paper Award

December 8th, 2017

photo of bowen song
Song given the Optical Society of America (OSA) sponsored award by its president Eric Mazur for the paper “Tunable 3D Integrated Hybrid Silicon Laser”

The ACP Best Student Paper Awards are given to students who are first authors and presenters of exceptional contributed talks and the selection was made by the subcommittees during the conference. Song presented on tunable 3D integrated hybrid silicon lasers that were demonstrated with side-mode suppression ratio of 43 dB, output power of 2 mW, laser linewidth of 1.5 MHz, and relative intensity noise of -132 dB/Hz. Additional authors of the paper include Sergio Pinna (UCSB), Sasa Ristic (McGill U) and ECE Professor Jonathan Klamkin (UCSB).

The Asia Communications and Photonics Conference (ACP) is the largest conference in the Asia-Pacific region on optical communication, photonics and relevant technologies. ACP has been held annually tracing back to 2001 and is jointly sponsored by OSA, SPIE, IEEE Photonics Society. The 2017 ACP was held in Guangzhou, China on November 10-13, 2017.

Song is currently a Ph.D. student in the ECE department at UCSB in Professor Jonathan Klamkin’s integrated photonics lab (iPL). His research focus is on 3D Hybrid integration for silicon photonics aimed to integrate laser or gain material to silicon chips; indium phosphide photonics integrated circuits and silicon phonics. In 2014 he received his Master of Science degree as a member of the Wide Bandgap Semiconductor Laboratory at Boston University working on developing nano-patterned sapphire substrate for AlGaN-based deep UV LEDs.

Asia Communications and Photonics Conference (ACP)

Song's Google Scholar page

ECE Professor Sanjit Mitra receives the IEEE Educational Activities Board (EAB) Vice-President’s Recognition Award

December 7th, 2017

sanjit mitra Mitra receives award for “outstanding contributions in analog and digital signal processing and image processing, and authoring pioneering textbooks that inspire and educate students worldwide”

IEEE Educational Activities Board (EAB) Awards recognize and honor major contributions to engineering and technical education. Awards are given for meritorious activities in accreditation, continuing education, educational innovation, pre-university education, service to the IEEE EAB, employee professional development, informal education systems, and related achievements that advance the practice of engineering and of engineering education.

The IEEE EAB awards are given out during the EAB Awards Ceremony, which is held in conjunction with the November IEEE Meeting Series each year.

Mitra is a Professor Emeritus at the University of California, Santa Barbara and the University of Southern California, in Los Angeles. He was the 1986 president of the IEEE Circuits and Systems Society. He has published more than 700 papers on analog and digital signal processing and image and video processing, and he has authored or coauthored 13 books. He holds six patents

The Institute – “Awards Honor People Making a Difference in Engineering Education”

COE website – "Sanjit Mitra: 50 Years of Signaling the Future"

IEEE Educational Activities Board (EAB) Awards

Mitra's COE Profile

UCSB’s Manjunath (ECE), Pollock (Materials), Miller (MSI) and teams from UCR and U. of AZ receive a $3.4M NSF grant to research scientific image processing

December 1st, 2017

illustration of a scientific imageUCSB researchers given the award from NSF’s Office of Advanced Cyberinfrastructure to build a large-scale distributed image-processing infrastructure (LIMPID) through a broad, interdisciplinary collaboration. Encompassing databases, image analysis and various scientific disciplines, their creation, BisQue, is an image informatics platform that shares, distributes and collaborates with large image datasets.

“Think of BisQue as Google Docs for scientific images,” said UCSB principal investigator B. S. Manjunath, who directs the campus’s Center for Multimodal Big Data Science and Healthcare. “Imaging data is ubiquitous and much of big-data science is image-centric. Working with such data should be as simple as working with text files in Google Docs.”

BisQue is unique in its ability to handle a wide range of imaging data across diverse scientific applications, ranging from marine and materials science to neuroscience and medical imaging. For example, Manjunath is working with co-PI Tresa Pollock, the Alcoa Distinguished Professor of Materials at UCSB, to integrate algorithms developed specifically for processing materials imaging data into BisQue. Recent advances in materials tomography (cross-sectional imaging) are generating an enormous quantity of imaging data that must be reconstructed, shared with the community and further analyzed. According to Pollock, “LIMPID will greatly enhance our ability to work with large material data sets and will leverage advances made in computer vision and machine learning.”

“In marine science, and particularly marine ecology, the technology to capture underwater images is growing exponentially, but most of the imaging data is manually processed,” said co-PI Robert Miller, a research biologist in UCSB’s Marine Science Institute. “In the Santa Barbara Channel Marine Biodiversity Observation Network, which is supported by NASA and the Bureau of Ocean Energy Management, we are developing image-analysis pipelines and models to process underwater imagery and automate the processes of identifying and quantifying marine organisms. LIMPID will expand that work dramatically to the point where UCSB will become the epicenter of image analysis technology for marine science.”

A team at UC Riverside, the home campus of LIMPID collaborator Amit Roy-Chowdhury, will work with neuroscience researchers to analyze large volumes of live imaging data that capture neuronal activities in the Drosophila nervous system. The UCSB scientists also are collaborating with Nirav Merchant of the University of Arizona, where BisQue and the cyberinfrastructure CyVerse will be leveraged to further enable image-based scientific discoveries.

The UCSB Current – "Share, Test and Refine" (full article)

UCSB Center for Bio-Image Informatics

Manjunath's COE Profile

ECE Professor Kaustav Banerjee’s work on novel quantum-transport simulator among most significant papers at IEDM 2017

November 30th, 2017

IEDM logo The selection of four IEDM papers on two-dimensional (2D) materials and devices from the Nanoelectronics Research Lab highlights its role in research on 2D electronics, as well as the interest in these materials in the semiconductor industry

At the upcoming IEEE International Electron Devices Meeting (IEDM), the technical program committee of the conference has selected Professor Banerjee’s work on a novel quantum-transport simulator as one of the sixteen most significant contributions from around 225 papers, which will be presented at the meeting during December 3-6 in San Francisco, CA, for pre-conference publicity. The work reports the first study of a critical leakage mechanism in 2D memory transistors, and establishes their superiority over silicon.

Prof. Banerjee’s selected paper titled “Computational Study of Gate-Induced Drain Leakage in 2D-Semiconductor Field-Effect Transistors” will be presented on Wed, December 6, 2017, in Session 31 by recent ECE alum Dr. Jiahao Kang. The paper is co-authored by several other members in his Nanoelectronics Research Lab (NRL) and researchers from Micron Technology.

In addition, three of Professor Banerjee’s current graduate students – Junkai Jiang, Arnab Pal, and Xuejun Xie – will each present a paper on new innovations on 2D Electronics at this meeting. The selection of four papers from a single research group is a significant achievement in IEDM, which has been the world’s leading forum for reporting innovation, discovery, and breakthroughs in electron device technology for over 60 years.

IEDM 2017 – Most Significant Papers

IEEE Spectrum: "Carbon Nanomaterials Could Push Copper Aside in Chip Interconnects"

Banerjee's Nanoelectronics Research Lab (NRL)

ECE Professor Chris Palmstrom & UCSB scientists are on the cusp of a major advance in topological quantum computing.

November 21st, 2017

Deterministic growth of InSb nanowire networks
Paper in the journal Nature describes a method by which “hashtag”– shaped nanowires may be coaxed to generate Majorana quasiparticles. These particles are exotic states that if realized, can be used to encode information with very little risk of decoherence — one of quantum computing’s biggest challenges — and thus, little need for quantum error correction.

“This was a really good step toward making things happen,” said Palmstrøm. In 2012, Dutch scientists Leo Kouwenhoven and Erik Bakkers (also authors on the paper) from the Delft and Eindhoven Universities of Technology in the Netherlands, reported the first observation of states consistent with these quasiparticles. At the time, however, they stopped short of definitive proof that they were in fact the Majoranas, and not other phenomena.

Under the aegis of Microsoft Corporation’s Research Station Q headquartered on the UCSB campus, this team of scientists is part of a greater international effort to build the first topological quantum computer.

“Quantum technology is now being advanced through large academic – industry collaborations,” said Michael Freedman, Fields Medal-winning mathematician and director of Station Q. “The scale of the work, in most cases, is too large for university labs alone, but the imagination and inventiveness of these labs make them essential partners in any industrial effort. Inventiveness and imagination is precisely what is on display in this recent collaboration involving UCSB, Delft, Eindhoven, Copenhagen, and Microsoft. The ‘hashtag’ structures whose quantum properties are studied in this paper have an unworldly beauty and look nearly as impossible as a tower by Escher. They are single crystals with the topology of a circle. Hats off to the grows and the experimentalists.”

The quasiparticles are named for Italian physicist Ettore Majorana, who predicted their existence in 1937, around the birth of quantum mechanics. They have the unique distinction of being their own antiparticles — they can annihilate one another. They also have the quality of being non-Abelian, resulting in the ability to “remember” their relative positions over time — a property that makes them central to topological quantum computation.

“If you are to move these Majoranas physically around each other, they will remember if they were moved clockwise or anticlockwise,” said Mihir Pendharkar, a graduate student researcher in the Palmstrøm Group. This operation of moving one around the other, he continued, is what is referred to as “braiding.” Computations could in theory be performed by braiding the Majoranas and then fusing them, releasing a poof of energy — a “digital high” — or absorbing energy — a “digital low.” The information is contained and processed by the exchange of positions, and the outcome is split between the two or more Majoranas (not the quasiparticles themselves), a topological property that protects the information from the environmental perturbations (noise) that could affect the individual Majoranas.

However, before any braiding can be performed, these fragile and fleeting quasiparticles must first be generated. In this international collaboration, semiconductor wafers started their journey with patterning of gold droplets at the Delft University of Technology. With the gold droplets acting as seeds, Indium antimonide (InSb) semiconductor nanowires were then grown at the Eindhoven University of Technology. Next, the nanowires traveled across the globe to Santa Barbara, where Palmstrøm Group researchers carefully cleaned and partially covered them with a thin shell of superconducting aluminum. The nanowires were returned to the Netherlands for low temperature electrical measurements.

“The Majorana has been predicted to occur between a superconductor and a semiconductor wire,” Palmstrøm explained. Some of the intersecting wires in the infinitesimal hashtag-shaped device are fused together, while others barely miss one another, leaving a very precise gap. This clever design, according to the researchers, allows for some regions of a nanowire to go without an aluminum shell coating, laying down ideal conditions for the measurement of Majoranas.

“What you should be seeing is a state at zero energy,” Pendharkar said. This “zero-bias peak” is consistent with the mathematics that results in a particle being its own antiparticle and was first observed in 2012. “In 2012, they showed a tiny zero-bias blip in a sea of background,” Pendharkar said. With the new approach, he continued, “now the sea has gone missing,” which not only clarifies the 2012 result and takes the researchers one step closer to definitive proof of Majorana states, but also lays a more robust groundwork for the production of these quasiparticles.

Majoranas, because of their particular immunity to error, can be used to construct an ideal qubit (unit of quantum information) for topological quantum computers, and, according to the researchers, can result in a more practicable quantum computer because its fault-tolerance will require fewer qubits for error correction.

“All quantum computers are going to be working at very low temperatures,” Palmstrøm said, “because ‘quantum’ is a very low energy difference.” Thus, said the researchers, cooling fewer fault-tolerant qubits in a quantum circuit would be easier, and done in a smaller footprint, than cooling more error-prone qubits plus those required to protect from error.

The final step toward conclusive proof of Majoranas will be in the braiding, an experiment the researchers hope to conduct in the near future. To that end, the scientists continue to build on this foundation with designs that may enable and measure the outcome of braiding.

“We’ve had the funding and the expertise of people who are experts in the measurements side of things, and experts in the theory side of things,” Pendharkar said, “and it has been a great collaboration that has brought us up to this level.”

Article from The UCSB Current – “Finding Majoranas”

Nature – "Epitaxy of Advanced Nanowire Quantum Devices"

Chris Palmstrøm Research Group

Palmstrøm's COE Profile

The Association for Computing Machinery (ACM) interviews ECE Professor Yuan Xie in their November 2017 “People of ACM – Bulletin”

November 15th, 2017

photo of yuan xie
“People of ACM” highlights the unique scientific accomplishments and compelling personal attributes of ACM members who are making a difference in advancing computing as a science and a profession. These bulletins feature ACM members whose personal and professional stories are a source of inspiration for the larger computing community.

What research area(s) is receiving the most of your attention right now?
I am looking at application-driven and technology-driven novel circuits/architectures and design methodologies. My current research projects include novel architecture with emerging 3D integrated circuit (IC) and nonvolatile memory, interconnect architecture, and heterogeneous system architecture. In particular, my students and I have put a lot of effort into novel architectures for emerging workloads with an emphasis on artificial intelligence (AI). These novel architectures include computer architectures for deep learning neural networks, neuromorphic computing, and bio-inspired computing.

In your recent book Die-Stacking Architecture co-authored with Jishen Zhao, you predict that 3D memory stacking will be a computer architecture design that will become prevalent in the coming years. Will you tell us a little about 3D memory stacking?
Die-stacking technology is also called three-dimensional integrated circuits (3D ICs). The concept is to stack multiple layers of integrated circuits vertically, and connect them together with vertical interconnections called through-silicon vias (TSVs). My research group has been working on die-stacking architecture for more than a decade. We’ve been looking at different ways to innovate the processor architecture designs with this revolutionary technology. Recently, memory vendors have developed multi-layer 3D stacked DRAM products, such as Samsung’s High-bandwidth Memory (HBM) and Micron’s Hybrid-Memory Cube (HMC). Using interposer technologies, processors can be integrated with 3D stacked memory into the same package, increasing the in-package memory capacity dramatically. The first commercial die-stacking architecture is the AMD Fury X graphic processing unit (GPU) with 4GB HBM die-stacking memory, which was officially released in 2015. Since then, we have seen many other products that integrate 3D memory, such as Nvidia’s Volta GPU, Google’s TPU2, and, most recently, Intel and AMD’s partnership on Intel’s Kaby Lake G series, which integrates AMD’s Radeon GPU and 4GB HBM2.

More questions & answers and Xie’s ACM Bio

  • How might the introduction of radically new hardware impact the existing ecosystem of software?
  • What are the possible architectural innovations in the AI era?

The Association for Computing Machinery (ACM)

Xie's COE Profile

Xie's Scalable Energy-efficient Architecture Lab (SEAL)