Fall 2020

Experiment takes “snapshots” of light, stops light, and uses light to change properties of matter

  • By Ke Xu
  • 21 December 2020

Light travels at a speed of about 300,000,000 meters per second as light particles, photons, or equivalently as electromagnetic field waves. Experiments led by Hrvoje Petek examined ideas surrounding the origins of light, taking snapshots of light, stopping light and using it to change properties of matter.

Petek worked with student Yannan Dai and collaborators Prof. Chen-Bin (Robin) Huang of the National Tsing Hua University in Taiwan, and Atsushi Kubo of the Tsukuba University of Japan on the experiments. Their findings were reported in the paper, “Plasmonic topological quasiparticle on the nanometre and femtosecond scales,” which was published in the Dec. 24 issue of Nature magazine.

Lillian Chong and Collaborators Receive Gordon Bell Special Prize for COVID-19 Research

  • By Jenny Stein
  • 1 December 2020

Prof. Lillian Chong and graduate student, Anthony Bogetti, were part of a multi-institution team effort that won the Association for Computing Machinery’s Gordon Bell Special Prize for High Performance Computing-Based COVID-19 Research, commonly referred to as the Nobel Prize of Supercomputing. A crowning achievement of this effort is the generation of atomically detailed views of how the spike protein of the coronavirus opens up before latching onto cells during infection.

Theoretical Reflections on Quantum Supremacy

Umesh Vazirani
Friday, December 4, 2020 - 3:30pm

Abstract: The recent demonstration of quantum supremacy by Google is a first step towards the era of small to medium scale quantum computers. In this talk I will explain what the experiment accomplished and the theoretical work it is based on, as well as what it did not accomplish and the many theoretical and practical challenges that remain. I will also describe recent breakthroughs in the design of protocols for the testing and benchmarking of quantum computers, a task that has deep computational and philosophical implications. Specifically, this leads to protocols for scalable and...

Pitt Researchers to Join NSF Materials Center Studying Two-Dimensional Metals

  • By Jenny Stein
  • 30 November 2020

The Nanoionics and Electronics Laboratory at the University of Pittsburgh’s Swanson School of Engineering has received $557,000 in funding from the National Science Foundation (NSF) for its work investigating a new type of two-dimensional material. The project, “Two-dimensional Polar Metals and Heterostructures,” is led by Associate Professor, Susan Fullerton, and Research Assistant Professor Ke Xu, both in the Department of Chemical and Petroleum Engineering.

PQI Seminar: Dr. Mario Hofmann, Dr. Ya-Ping Hsieh

Dr. Mario Hofmann and Dr. Ya-Ping Hsieh from the National Taiwan University and Academia Sinica gave a talk titled "Why and How to Integrate 2D Materials in Future Electronics" in the Pittsburgh Quantum Institute Fall Seminar series on Nov. 17th, 2020.

Abstract: 2D materials are atomically thin nanostructures that are considered enabling elements in future electronics due to their unique geometry and exciting physical properties. To realize such applications, however, challenges in materials quality and production have to be addressed. In this talk we will first introduce a novel growth method that can enhance the scale, reliability, and controllability of 2D materials synthesis. Through control of the gas phase kinetics of the chemical vapor deposition process, efficient 2D materials growth could be achieved in atomically confined conditions. This advance permits the synthesis of 2D materials, such as graphene and TMDCs, at unprecedented scale and at crystalline qualities that rival exfoliated materials. Moreover, synthesis in the van-der-Waals gap of a host 2D material is demonstrated to facilitate a novel 2D crystallization process that yields novel transition-metal monochalcogenides with unexpected thermodynamic properties and finely adjustable thickness. Finally, the atomic length scales in confined growth enable controllable multi-precursor synthesis of diluted magnetic semiconductor 2D materials. The high quality of thus grown materials reveal novel interfacial ordering effects of 2D materials that are fundamentally different from bulk and present both challenges and opportunities towards their integration in electronics. Organization of ionic impurities on high quality graphene was shown to introduce a novel scattering process, that modulates graphene’s mobility by six times and is independent of charge concentration, necessitating improvements in materials’ characterization and handling. On the other hand, ordering effects at 2D materials interfaces can provide routes towards enhanced fabrication and performance of electronic devices. Interaction of graphene surfaces with gaseous adsorbates was shown to stabilize graphene in chemical reactions, permitting atomic-precision lithography approaches for large-scale semiconductor fabrication. Finally, assembly of monolayer water films on graphene under nanomechanical confinement was shown to produce a novel ferroelectric ice phase that can be exploited in mechanical memristive devices.

Duquesne University Announces New Professional Masters Degree in Applied Physics

  • By Jenny Stein
  • 27 November 2020

Duquesne University is happy to announce the opening of a new Professional Masters degree in Applied Physics, beginning Fall 2021. The new program combines hands-on experience with optics, instrumentation, and materials with business skills to enable graduates to enter industry or to start their own tech company. Please see their website for more information and how to apply.

Heusler alloys for Spin Transport

Paul Crowell
Friday, November 20, 2020 - 12:00pm

Abstract: It has been widely appreciated that Heusler alloys (e.g., Co2MnSi) can be half-metallic, meaning that there is a gap for one spin state at the Fermi level. It is in principal possible to use this feature to generate currents that are 100% spin-polarized. Unfortunately, exploiting this characteristic in real devices, which necessarily include interfaces between dissimilar materials, represents a far greater challenge. This seminar will focus on observations about epitaxial Heusler alloys grown on GaAs and MgO. I will discuss why we are interested in the microwave...

Peyman Givi Receives NSF Award to Study Complex Turbulent Flows

  • By Jenny Stein
  • 18 November 2020

​​​​​​​Mechanical engineering professors Hessam Babaee and Peyman Givi recently received an award from the National Science Foundation (NSF) for a three-year project titled “Real-Time and Adaptive Chemical Kinetic Model Reduction Coupled with Turbulence.” 

The chemistry of combustion involves understanding how a large number of species behave and evolve in a given operating condition.  The tractability of this technically important problem becomes increasingly difficult when the operation involves turbulent mixing. 

Quantum2020 Poster Session Winners

  • By Jenny Stein
  • 13 November 2020

The Quantum2020 Spooky Action at a Distance poster session was held remotely over multiple Zoom sessions on October 29th, 2020. We had a team of 20 judges coming from various departments at Pitt, CMU, and Duquesne comprising both faculty members, postdocs and previous poster award winners, who evaluated the poster presentations of 44 participants hailing from physics, engineering, chemistry, and other disciplines. 

The full video playlist is linked here, and the descriptions of each video contain quicklinks to the beginning of each presentation. Thank you to everyone who participated!

The six presenters that received the highest overall scores are: 

PQI Seminar: Dr. David Wallace

Dr. Dave Wallace from the University of Pittsburgh gave a talk titled "What is 'Orthodox' Quantum Mechanics?" in the Pittsburgh Quantum Institute Fall Seminar series on Nov. 12th, 2020.

Abstract: What is called "orthodox'' quantum mechanics, as presented in standard foundational discussions, relies on two substantive assumptions --- the projection postulate and the eigenvalue-eigenvector link --- that do not in fact play any part in practical applications of quantum mechanics. I argue for this conclusion on a number of grounds, but primarily on the grounds that the projection postulate fails correctly to account for repeated, continuous and unsharp measurements (all of which are standard in contemporary physics) and that the eigenvalue-eigenvector link implies that virtually all interesting properties are maximally indefinite pretty much always. I present an alternative way of conceptualizing quantum mechanics that does a better job of representing quantum mechanics as it is actually used, and in particular that eliminates use of either the projection postulate or the eigenvalue-eigenvector link, and I reformulate the quantum measurement problem within this new presentation of orthodoxy.