Spring 2019

Feng Xiong Recieved NSF Award for Thermoelectric Semiconductor Research

  • By Huiling Shao
  • 8 April 2019

Feng Xiong and Jonathan Malen, received a $500,000 award from the National Science Foundation to develop a thermoelectric semiconductor using tungsten disulfide to convert waste heat into energy. Using a novel doping approach, they will enhance the tungsten disulfide’s electrical conductivity while lowering its thermal conductivity—it will be able to efficiently conduct electricity without conducting heat. Tungsten disulfide is thin and flexible, making it a promising new option with diverse potential uses. 

The project length is three years, with a possible extension into a fourth. The award is split between Dr. Xiong’s lab ($270,000) and Dr. Malen’s lab ($230,000). The team will work closely with local communities to encourage students from all backgrounds to explore engineering careers and foster interest in nanotechnology. Outreach efforts will include lab demonstrations, summer internships and career workshops.

Benchmark NISQ Devices using State-of-the-art Classical Tools

Speaker(s): 
Salvatore Mandra
Dates: 
Tuesday, April 2, 2019 - 4:00pm

In the race to show quantum advantage, early Noisy Intermediate-Scale Quantum (NISQ) devices must be compared to the state-of-the-art classical technology currently available. At the Quantum Artificial Intelligence Lab (QuAIL) at NASA Ames, we are continuously developing new classical algorithms to benchmark/validate quantum hardware and to raise the bar to claim quantum advantage. In my talk, I will present our optimized classical simulator for large quantum circuits, including numerical simulations of the Google Bristlecone quantum processing unit.

Quantum Computing based on Trapped Ion Technology

Speaker(s): 
Dr. Jungsang Kim
Dates: 
Wednesday, April 3, 2019 - 12:00pm

Trapped ions are one of the leading candidates for realizing practically useful quantum computers. Introduction of advanced integration technologies to this traditional atomic physics research has provided an opportunity to convert a complex atomic physics experiment into a stand-alone programmable quantum computer. In this presentation, I will discuss the new enabling technologies that changes the perception of a trapped ion system as a scalable quantum computer, and the concrete progress made to date in this endeavor. I will also discuss potential application areas where quantum...

Latest research from Jeremy Levy Lab: Over 100-THz bandwidth selective difference frequency generation at LaAlO3/SrTiO3 nanojunctions

  • By Huiling Shao
  • 19 March 2019

The ability to combine continuously tunable narrow-band terahertz (THz) generation that can access both the far-infrared and mid-infrared regimes with nanometer-scale spatial resolution is highly promising for identifying underlying light-matter interactions and realizing selective control of rotational or vibrational resonances in nanoparticles or molecules. Here, we report selective difference frequency generation with over 100 THz bandwidth via femtosecond optical pulse shaping. The THz emission is generated at nanoscale junctions at the interface of LaAlO3/SrTiO3 (LAO/STO) that is defined by conductive atomic force microscope lithography, with the potential to perform THz spectroscopy on individual nanoparticles or molecules. Numerical simulation of the time-domain signal facilitates the identification of components that contribute to the THz generation. This ultra-wide-bandwidth tunable nanoscale coherent THz source transforms the LAO/STO interface into a promising platform for integrated lab-on-chip optoelectronic devices with various functionalities.

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Peyman Givi will co-chair mini symposium at 17th International Conference on Numerical Combustion

  • By Huiling Shao
  • 19 March 2019

Peyman Givi, developer of the Filtered Density Function (FDF) used in very high fidelity numerical simulation of chemically reactive flow fields, will co-chair a mini symposium on the subject at the 17th International Conference on Numerical Combustion (NC19) in Aachen, Germany from May 6-8, 2019. The mini symposium “Filtered Density Function Methods for Turbulent Reactive Flows” will include 60 participants and 28 presented papers. According to Dr. Givi, participants will learn the latest developments and innovations in enhancing the computational and predictive capabilities of the FDF methodology.

Sangyeop Lee's Research on ab initio Phonon Thermal Transport Published in Materials Today Physics

  • By Huiling Shao
  • 12 March 2019

Sangyeop Lee is co-author of a recent article, “Survey of ab initio phonon thermal transport” in Materials Today Physics (vol. 7, 2018, pp. 106-120, DOI 10.1016/j.mtphys.2018.11.008). This article provides a comprehensive survey of first-principles Peierls-Boltzmann thermal transport as developed in the literature over the last decade, with particular focus on more recent advances. This review will demonstrate the wide variety of calculations accessible to first-principles transport methods (including dimensionality, pressure, and defects), highlight unusual properties and predictions that have been made, and discuss some challenges and behaviors that lie beyond.

Dr. Lee, who joined Pitt in 2015, studies nanoscale thermal transport in solid materials, and his research is currently focused on hydrodynamic phonon transport in graphitic materials and thermal transport in fully or partially disordered phase. His group utilizes Boltzmann transport theory, Green's function method, and molecular dynamics simulation, all of which use interatomic force constants calculated from density functional theory. He earned his BS and MS in mechanical and aerospace engineering from the Korea Advanced Institute of Science and Technology, and PhD in mechanical engineering from MIT. 

Written by Paul Kovach. 

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A look inside the black box of scientific publishing

Speaker(s): 
Dr. Matteo Cavalleri
Dates: 
Friday, March 15, 2019 - 10:00am

Publishing the results of one’s research is an integral part of the scientific process, yet scholarly journals are often seen as black boxes by researchers. What happens to a paper after it is submitted? Who is deciding on its fate? What is the role of the journal editor and the editorial office? How does the peer-review process work, and are its core principles still relevant in today’s changing publishing landscape? 
In this talk I will discuss these questions in an attempt to de-mystify the peer review process from an editor's perspective, and provide advice for getting your...

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