Fall 2020

Detecting Acoustic Blackbody Radiation

  • By Jenny Stein
  • 22 September 2020

As objects heat up, they not only glow but also emit acoustic energy. This “acoustic blackbody radiation” may be as ubiquitous as its more famous electromagnetic cousin but is typically faint and difficult to characterize. Now, a pair of researchers, Thomas Purdy and Robinjeet Singh, have used a nanomechanical resonator to detect acoustic blackbody radiation from a remote source [1]. They say their technique—the acoustic analog of remote infrared thermometry—could lead to improvements in applications ranging from metrology to quantum information.

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.

Gurudev Dutt Wins Award in Million Dollar International Quantum U Tech Accelerator

  • By Jenny Stein
  • 7 September 2020

The Innovare Advancement Center, a partnership between the Air Force Research Laboratory Information Directorate (AFRL/RI), New York State, and others, hosted a unique quantum-focused virtual pitch competition, the “Million Dollar International Quantum U Tech Accelerator,” on September 1-3 to launch their new open innovation campus in Rome, NY.

The goal of the competition was to encourage university researchers that pursue high impact projects in quantum timing, sensing, information processing/computing, and communications/networking to bring a new quantum phenomenon into the military while offering about $1,000,000 to the finalists.

Even with nearly 250 teams from 22 countries submitting proposals to take part in the competition, two PQI faculty, Dr. Tom Purdy and Dr. Gurudev Dutt, were among the top 36 selected to take part in the live pitch event, each giving a 10-minute presentation with Q&A (watch presentations from Tom and Gurudev). Ultimately, 18 finalists were selected for the $1M+ in basic research funds and Gurudev won in the topic of quantum sensing.

Microwaving New Materials

  • By Ke Xu
  • 24 August 2020

Reeja Jayan and her student Nathan Nakamura has made a breakthrough in our understanding of how microwaves affect materials chemistry. Unlike prior studies, which suffered from the inability to monitor structural changes while the microwaves were applied, Jayan developed novel tools (a custom-designed microwave reactor enabling in-situ synchrotron x-ray scattering) for studying these dynamic, field-driven changes in local atomic structure as they happen. By revealing the dynamics of how microwaves affect specific chemical bonds during the synthesis, Jayan is laying the groundwork for tailor-made ceramic materials with new electronic, thermal, and mechanical properties. Building on this concept, she is investigating how to use microwaves to engineer new materials.

The results of Jayan’s research were published in the Journal of Materials Chemistry AThe paper was recognized as part of the 2020 Emerging Investigators Issue of the journal.

Critical pattern formation at the Mott metal-insulator transition

Speaker(s): 
Erica Carlson
Dates: 
Monday, November 2, 2020 - 4:00pm

Joint Pitt/CMU Colloquium

Critical pattern formation at the Mott metal-insulator transition

Abstract:

I discuss the critical pattern formation of metallic and insulating nanoscale domains observed in NdNiO3 and VO2, via scanning near-field optical microscopy. The electronic phase transitions of these materials hold promise for novel ways to encode and process information, of interest for developing memristors and neuromorphic devices. Using theoretical tools from fractal mathematics and disordered statistical mechanics, we use the rich spatial information of this...

What does it Take to Build a Quantum Computer

Speaker(s): 
Chris Lirakis
Dates: 
Thursday, October 1, 2020 - 4:00pm

Abstract: IBM has been working on realizing a quantum computer since the idea first surfaced in 1982. Early instantiations were photon-based and proved that indeed bit like information could be stored in a quantum state. Since then many different modalities have sprung up, Trapped Ions and Superconducting qubits being the most popular. The IBM systems are on the path to error correction. However, we still have a long way to go. The path to success will be paved by wide scale acceptance and training in these using this new computational paradigm. All manner of expertise will be important on...

Antisymmetry: Fundamentals and Applications

Speaker(s): 
Venkat Gopalan
Dates: 
Thursday, September 17, 2020 - 4:00pm

Symmetry is fundamental to understanding our physical world.  An antisymmetry operation switches between two different states of a trait, such as two time-states, position-states, charge-states, spin-states, chemical-species etc.   This talk will cover the fundamental concept of antisymmetry, with brief mentions of two well-established antisymmetries, namely spatial inversion in point groups and time reversal. Then it will introduce two new ones, namely, distortion reversal and wedge reversion.  The distinction between classical and quantum mechanical descriptions of time reversal will be...

Spin and Orbital Resonance Driven by a Mechanical Resonator

Speaker(s): 
Greg Fuchs
Dates: 
Monday, September 14, 2020 - 4:00pm

Zoom access can be found in the PQI weekly newsletter or by contacting jennifer.stein@pqi.org

Abstract: I will describe our experiments to drive spin and orbital resonance of single diamond nitrogen-vacancy (NV) centers using the gigahertz-frequency strain oscillations produced within a diamond acoustic resonator. Strain-based coupling between a resonator and a defect center takes advantage of intrinsic and reproducible coupling mechanisms while maintaining compatibility with conventional magnetic and optical techniques, thus providing new...

Rings and tunnel junctions: Quantum mechanics on a circle

Speaker(s): 
Arthur Davidson
Dates: 
Thursday, September 10, 2020 - 4:00pm

We show by standard quantum principles that two circuits, a small tunnel junction and a small metal loop with an electron, are related by a gauge transformation. We show further that this same transform prevents momentum eigen functions from having gauge invariant de Broglie wave lengths around a ring. Thus persistent current on a metal ring and the Coulomb blockade on a small tunnel junction seem to be the same dynamical theory based on discontinuous Bloch waves on the perimeter of a circle. This is historically an area of simple quantum circuits where the principle of gauge invariance...

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