Featured

Geoff Hutchison wins 2018 Tina and David Bellet Excellence Award

  • By Burcu Ozden
  • 7 February 2018

Geoff Hutchison is the 2018 Tina and David Bellet Excellence Awardee. The award recognizes his effectiveness and his innovations in teaching. Among many innovations Hutchinson developed Avagadro molecular editor; with that software, he designed projects hat allow Physical Chemistry students to perform quantum mechanical calculations to visualize results/concepts. 

Frolov and Team Featured on Pitt Website

  • By Burcu Ozden
  • 12 January 2018

PQI Members Sergey Frolov, David Pekker, Noa Marom, Michael Hatridge, Benjamin Hunt, and Hrvoje Petek featured on Pitt Website for their accomplisment on landing $4.8M award from National Science Foundation (NSF) for International Research and Education (PIRE) program.Sergey Frolov will be the Director of new PIRE.  Hrvoje Petek, Michael Hatridge and David Pekker are other PQI co-PIs for this project. The duration of the program is 5 years.

Four-dimensional physics in two dimensions

  • By Leena Aggarwal
  • 5 January 2018

Kevin Chen and team have demonstrated that the behavior of particles of light can be made to match predictions about the four-dimensional version of the "quantum Hall effect"—a phenomenon that has been at the root of three Nobel Prizes in physics—in a two-dimensional array of "waveguides."

“For the first time, physicists have built a two-dimensional experimental system that allows them to study the physical properties of materials that were theorized to exist only in four-dimensional space"

Understanding of the superior stability of Silicon- and oxygen-containing hydrogenated amorphous carbon in harsh environments

  • By Leena Aggarwal
  • 3 January 2018

Recently, Tevis D. B. Jacobs and colleagues have shown how silicon- and oxygen-containing hydrogenated amorphous carbon (a-C:H:Si:O) coating enhance the thermal stability in vacuum, but tremendously increases the thermo-oxidative stability and the resistance to degradation upon exposure to the harsh conditions of low Earth orbit (LEO). These findings provide a novel physically-based understanding of the superior stability of a-C:H:Si:O in harsh environments compared to a-C:H.

PQI Seminar: Dr. Jim Freericks

Dr. Jim Freericks from Georgetown University gave a talk titled "Operator Mechanics: A new form of quantum mechanics without waves or matrices" in the Pittsburgh Quantum Institute Fall Seminar series on Sept. 3rd, 2020.

His presentation slides can be found here: https://drive.google.com/drive/folders/1zLohpkcooZx7fPrht0gZOfWvBg9Ja34B

Abstract: Quantum mechanics was created with the matrix mechanics of Heisenberg, Born, and Jordan. Schroedinger's wave mechanics shortly followed and allowed for simpler and more powerful calculations. Both Pauli and Dirac introduced a formulation of quantum mechanics based on operators and commutation relations, but it was never fully developed in the 1920's. Instead, Schroedinger formulated the operator approach with his factorization method, which later was adopted by the high-energy community as supersymmetric quantum mechanics. In this talk, I will explain how one can formulate nearly all of quantum mechanics algebraically by a proper use of the translation operator on top of Schroedinger's factorization method. I will give examples of how one can compute spherical harmonics algebraically, how one can find harmonic oscillator wavefunctions, and will even describe an operator-based derivation of the wavefunctions of Hydrogen. I will end with a proposal for a novel way to teach quantum mechanics, focusing first on conceptual ideas related to superposition, projective measurements, and entanglement. Then developing more conventional topics like spin, harmonic oscillator, angular momentum, interacting spin models, central potentials, particles in a box and so on. This is the subject of a book in progress entitled Quantum Mechanics without Calculus.

PQI Profiles: Hideo Mabuchi

Professor Hideo Mabuchi from Stanford University talks about joining the Caltech faculty straight out of graduate school, coherent Ising machines, and learning to take oneself seriously.

Hideo Mabuchi received an AB in Physics from Princeton and a PhD in Physics from Caltech.  He served as Chair of the Department of Applied Physics at Stanford from 2010-2016.  His early scientific research was focused on understanding open quantum systems, quantum measurement, and the quantum-to-classical transition.  In recent years his research group has turned towards fundamental issues of quantum engineering, such as quantum nonlinear dynamics, quantum feedback control and quantum model reduction.  Along the way his group has also worked substantially on single-molecule biophysics, quantum information science, and quantum materials.  In parallel with directing his group's sponsored research, Hideo has developed a deep personal interest in exploring the interfaces of modern science with traditional craft, aesthetic philosophy and new materialism.  He has been experimenting with novel teaching initiatives to help resurrect the ideals of liberal education in the modern university.

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. 

Move aside sliced bread, we've got a new phase of matter

  • By Jenny Stein
  • 18 February 2020

A research team led by professors from the University of Pittsburgh Department of Physics and Astronomy has announced the discovery of a new electronic state of matter. PQI members Jeremy Levy, Patrick Irvin, David Pekker, and Roger Mong are coauthors of the paper "Pascal conductance series in ballistic one-dimensional LaAIO3/SrTiO3 channels." The research focuses on measurements in one-dimensional conducting systems where electrons are found to travel without scattering in groups of two or more at a time, rather than individually. The study was published in Science on Feb. 14. Jeremy also breaks down the scientific concepts and guides the readers through their research in the following video.

First Universal Computer Model for Metal Nanoparticle Adsorption

  • By Ke Xu
  • 16 September 2019

New research from the Giannis (Yanni) Mpourmpakis and his team introduces the first universal adsorption model that accounts for detailed nanoparticle structural characteristics, metal composition and different adsorbates, making it possible to not only predict adsorption behavior on any metal nanoparticles but screen their stability, as well. The research combines computational chemistry modeling with machine learning to fit a large number of data and accurately predict adsorption trends on nanoparticles that have not previously been seen. By connecting adsorption with the stability of nanoparticles, nanoparticles can now be optimized in terms of their synthetic accessibility and application property behavior. This improvement will significantly accelerate nanomaterials design and avoid trial and error experimentation in the lab. Their work was published in Science Advances on Sept. 13, 2019.

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.

Read more here

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