Summer 2020

Machine learning used to up-cycle waste carbon

  • By Jenny Stein
  • 22 May 2020

Researchers at University of Toronto Engineering and Carnegie Mellon University are using artificial intelligence (AI) to accelerate progress in transforming waste carbon into a commercially valuable product with record efficiency.

They leveraged AI to speed up the search for the key material in a new catalyst that converts carbon dioxide (CO2) into ethylene -- a chemical precursor to a wide range of products, from plastics to dish detergent.

The resulting electrocatalyst is the most efficient in its class. If run using wind or solar power, the system also provides an efficient way to store electricity from these renewable but intermittent sources.

"Using clean electricity to convert CO2 into ethylene, which has a $60 billion global market, can improve the economics of both carbon capture and clean energy storage," says Professor Ted Sargent, one of the senior authors on a new paper published today in Nature.

Chandralekha Singh Becomes President of AAPT

  • By Jenny Stein
  • 15 May 2020

​​​​​​​During the 2020 Winter Meeting in Orlando, Florida, the presidential gavel was presented to Dr. Chandralekha Singh. She will serve as President of the American Association of Physics Teachers for the coming year. Singh, Professor in the Department of Physics and Astronomy and Founding Director of the Discipline-based Science Education Research Center at the University of Pittsburgh, has previously served on the AAPT Board of Directors as President-elect and Vice President.

Regarding her service to AAPT, Singh said, "This position comes with the opportunity to lead an organization that I revere and work with dedicated and enthusiastic colleagues who share my passion for enhancing the understanding and appreciation of physics through teaching."

Anatomy of a Photonic QPU

Speaker(s): 
Eric Johnston
Dates: 
Tuesday, May 19, 2020 - 12:30pm

In building a full-scale QPU, problems of decoherence, scaling, manufacturability, and networking can be solved by using photons as the computational qubits. This also causes some interesting new problems, such as how to wrangle them. Starting with the notation from the Octopus Book, we'll go a bit further, to look at ridiculously-complicated graph states and measurement-based computation. Then we'll go much further, outlining a rough design for a scalable, fault-tolerant photonic QPU.

Bio: Eric R. Johnston ("EJ") (U.C. Berkeley EECS '92) is co-...

Batteries for Flying Cars

  • By Jenny Stein
  • 8 May 2020

Venkat Viswanathan, Associate Professor of Mechanical Engineering at CMU, describes their latest paper in Nature Materials and the 5-year effort to understand electrodeposition instabilities at solid-solid interfaces, leading to high-performing lithium metal based batteries:

In the fall of 2015, we began exploring the role of mechanical properties in stabilizing lithium electrodeposition at solid-solid interfaces in solid state batteries. Previous results from an elegant linear stability analysis performed by Monroe and Newman suggested that solids with sufficiently large moduli could block dendrite growth due to the stabilizing role of the hydrostatic part of the stress.

How to Dress a Metal

  • By Jenny Stein
  • 6 May 2020

Research describing how an optical field can modify the electronic properties of a solid was recently published in Nature Communications titled "Coherent multidimensional photoelectron spectroscopy of ultrafast quasiparticle dressing by light", coauthored by Dr. Marcel Reutzel, Hrvoje Petek, and Petek's students Andi Li and Zehua Wang.

Applying intense ultrafast light pulses, which provide a time-periodic electronic potential acting together with the lattice ions, defines the forces experienced by electrons in solids, such as metals and semiconductors, Petek and his coworkers demonstrated that an optical field can transiently, on the 10-14 second time scale, modify (dress) the electronic bands in a metal, potentially changing them from an electron to a hole condition. 

Coherent nonlinear dynamics and the physics of computation [remote]

Speaker(s): 
Hideo Mabuchi
Dates: 
Thursday, June 11, 2020 - 3:30pm

The lecture will be livestreamed from our PQI YouTube channel or viewed in the video below. Questions from the audience will be accepted via the YouTube live channel chat.

Lecture abstract: The Coherent Ising Machine (CIM) is an emerging unconventional computing architecture for non-convex optimization.  By construction, CIMs leverage an interplay between...