Pappalardo Fellowships Symposium

Spring 2025 Annual Pappalardo Fellowships in Physics Symposium

THURSDAY, APRIL 3, 2025

*All events take place at the Cambridge Marriott, Kendall Square, 50 Broadway, Cambridge, MA*

SCHEDULE OF EVENTS

:: 1:00 – 2:00 PM

RECEPTION

:: 2:00 – 2:15 PM

INTRODUCTORY REMARKS

Or Hen, Associate Professor of Physics, MIT; 2015-2017 Pappalardo Fellow

:: 2:15 – 2:45 PM

Brooke Russell, The Neil and Jane Pappalardo Special Fellow in Physics (experimental nuclear & particle physics)

“A Novel Pixel Technology to Enable Precision Oscillation Measurements at the Neutrino Frontier”

Neutrinos are the most abundant massive particle in the universe. Although they are ubiquitous, much remains unknown about their underlying properties. Studying the neutrino is a unique challenge, owing to their extraordinarily small mass and rarity of interaction. I develop pixel sensors to natively capture 3D images of neutrino-nucleus interactions at the millimeter scale in multi-tonne noble liquid detectors. This novel technology was developed to meet the demands of next-generation neutrino oscillation experiments, which will operate in an unprecedented experimental regime to elucidate the mystery of the neutrino. In this talk, I will frame the experimental challenge to precisely measure neutrino mixing parameters in the context of pixelated charge readout system architecture development.

:: 2:45 – 3:15 PM

Benjamin Lehmann, 2022-2025 Pappalardo Fellow (high energy & particle theory physics)

“Finding primordial black holes wherever they may hide”

Over the last ten years, new observational tools have made it possible to study black holes in unprecedented detail. But a fundamental question remains unanswered: where do most black holes come from? In addition to those produced by stellar collapse, black holes may be produced in the extreme conditions of the early universe—and these primordial black holes might be so abundant that they could account for all of cosmological dark matter. In this scenario, however, primordial black holes would be microscopic, barely larger in radius than a hydrogen atom, and thus extremely difficult to detect. I will share recent ideas that leverage new and old observables, including measurements of our own Solar System, to achieve unprecedented sensitivity to these tiny objects. These probes promise to finally put the hypothesis of black holes as dark matter to the test.

:: 3:15 – 3:45 PM

Sepehr Ebadi, 2024 – 2027 Pappalardo Fellow (experimental atomic/nuclear & particle physics)

“Radioactive molecules as probes of fundamental physics”

Why is there more matter in the observable universe than antimatter? The Standard Model of particle physics – a triumph of the twentieth century – fails to explain this cosmological observation, motivating a broad search for physics beyond the standard model. Remarkably, any physical theory that could explain this mystery (and several others like it) would also predict small yet detectable shifts in the spectra of atoms and molecules. For instance, any theory explaining the matter-antimatter asymmetry postulates excess symmetry-violating interactions compared to the standard model, therefore predicting a larger electric dipole moment (EDM) in electrons or nuclei – a moment almost forbidden by the standard model.

I will present our work towards a precision measurement of an EDM in the nuclei of radioactive molecules. Specifically, polar molecules containing heavy radium atoms offer nuclear deformations that enhance nuclear EDMs, relativistic effects offering extremely large intramolecular electric fields, and electronic structure suitable for laser cooling and quantum control hence enabling long coherence times. This unique combination of properties offers a millionfold increased sensitivity compared to existing atomic searches – allowing us to probe unknown particles and fields at scales reaching 100s of TeV, much larger than the reach of any current particle collider. To this end, we are building a unique cryogenic vacuum apparatus, extremely sensitive laser excitation and imaging optics, and infrastructure for handling radioactive samples. In this talk I will report on our construction progress toward laser cooling the heaviest species to date while overcoming challenges associated with radioactivity.

:: 3:45 – 4:00 PM 

INTERMISSION

:: 4:00 – 4:30 PM

Jiaqi Cai, 2024-2027 Pappalardo Fellow (experimental condensed matter physics)

“Electron Choreography in Flatland: from Hall Effect to Zero-field Anyons”

Electrons, much like dancers, follow intricate choreographies dictated by the forces around them. In the classical Hall effect, they perform a simple, orderly waltz—marching sideways under a magnetic field. Moving into the quantum Hall regime, their motion transforms into a precise, synchronized ballet, dictated by quantized cyclotron orbits.

However, in the fractional quantum Hall effect (FQHE), the choreography becomes far more mysterious. Electron motion is no longer a clear-cut dance but a quantum improvisation, where individual trajectories dissolve into a fuzzy, entangled swirl of probability. If you focus on one dancer at a time, their behavior no longer resembles individual electrons but rather fractionalized quasiparticles—anyons—moving to a rhythm that defies classical intuition.

Most remarkably, the recently discovered fractional quantum anomalous Hall effect (FQAHE) eliminates the need for an external magnetic field, allowing electrons to engage in a self-sustained, topologically protected quantum tango without any conductor. In this exotic state, topology and strong correlation dictate an intricate electronic dance that could revolutionize our understanding of quantum materials and pave the way for breakthroughs in quantum computing.

:: 4:30 – 5:00 PM

Richard Nally, 2024 – 2027 Pappalardo Fellow (string theory)

“A Home in the Landscape?”

A fundamental, experimentally observed feature of our universe is that we have a positive cosmological constant: not only is our universe expanding, but its expansion is accelerating. In string theory, our universe is believed to come from a “compactification,” a solution of the ten-dimensional theory where six of the dimensions are small, but it has been frustratingly difficult to find compactifications that reproduce this accelerating behavior. For the last twenty years, the construction of solutions of string theory with a positive cosmological constant has been a key challenge facing the field, but until recently the search had been in vain. In this talk, I will review recent work that yielded the first examples of string compactifications with positive cosmological constants.

Other Pappalardo links:

Thursday, October 24, 2024

  • Prof. Pablo Jarillo-Herrero
    Cecil and Ida Green Professor of Physics, MIT and Chair of the Pappalardo Fellowship Comittee (2018-2021)
    Introductory Remarks
  • Prof. Ashvin Vishwanath
    George Vasmer Leverett Professor of Physics, Harvard University
    Pappalardo Fellow, 2001-2004
    “Decoding the magical behavior of electrons in moire’ lattices”
  • Prof. Jocelyn Monroe, Professor of Particle Physics, University of Oxford
    Pappalardo Fellow in Physics, 2006-2009
    “Searching for Dark Matter: What Have We Learned in the Last 25 Years?”
  • Prof. Nitya Kallivayalil, Professor, Dean’s Research Fellow, GECO management committee; Director of Graduate Admissions, The University of Virginia
    Pappalardo Fellow in Physics, 2007-2010
    “Local Group Cosmology: lessons from mapping the stellar populations of the nearby universe”
  • Prof. Benjamin Safdi, Associate Professor, University of California, Berkeley
    Pappalardo Fellow, 2014-2017
    “On the verge of discovery: axion dark matter”
  • Prof. Marin Soljačić, Cecil and Ida Green Professor of Physics, MIT
    Pappalardo Fellow, 2000-2003
    “Some intersections of AI and science”

Thursday, March 16, 2023

Thursday, March 16, 2023

Thursday, April 28, 2022

Or Hen
Class of 1956 Career Development Associate Professor of Physics
2015-2017 Pappalardo Fellow

“Neutron Star Droplets and the Quarks Within”

Since the discovery of quarks nuclear physicists have been trying to understand the relation between the lower-resolution description of nuclei using protons and neutrons, and their underlying higher-resolution description in terms of quarks and gluons.

At the intersection of these two paradigms are Short-Range Correlations (SRC): pairs of strongly interacting nucleons whose distance is comparable to their radii.

Due to their overlapping quark distributions and strong interaction, SRC pairs reach local densities comparable to those existing in the outer core of neutron stars and serve as a bridge between low-energy nuclear structure, high-density nuclear matter and high-energy quark distributions.

In this talk, I will present results from high-energy electron scattering experiments that probe the structure and properties of SRCs across scales: from their effect on the behavior of protons in neutron-rich nuclear systems through their role in our understanding of strong interactions at short distances, and the impact of nuclear interactions on internal quark-gluon sub-structure of nuclei. 

Looking to the future I will also discuss next generation studies at the forthcoming Electron-Ion Collider under construction at Brookhaven National Lab.

Webcast recording: https://youtu.be/Hi5Hb1nciTY

  • April 4, 2021
    Katelin Schutz, 2019-2020 Pappalardo Fellow; 2020 NASA Einstein Fellow
    (Nuclear and Particle Theory)
    “Making Dark Matter Out of Light”
    Introductory remarks: Tracy Slatyer, Jerrold R. Zacharias Career Development Associate Professor of Physics
  • April 28, 2021
    Anna-Christina Eilers, 2019-2022 NASA Hubble Fellow; 2022-2024 Pappalardo Fellow
    (Astrophysics)
    “The Formation and Growth of Supermassive Black Holes”
    Introductory remarks: Robert Simcoe, Francis L. Friedman Professor of Physics; Director, MIT Kavli Institute for Astrophysics and Space Research
  • May 5, 2021
    Rachel Carr, 2016-2018, 2020-2021 Pappalardo Fellow
    (Experimental Nuclear and Particle Physics)
    Chasing Anomalies with Reactor Neutrinos”
    Introductory remarks: Janet Conrad, Professor of Physics
  • May 12, 2021
    Nicholas Kern, 2020-2023 Pappalardo Fellow
    (Astrophysics)
    “Ushering in a New Era for High Redshift Astrophysics and Cosmology with the 21 cm Line”
    Introductory remarks: Jacqueline Hewitt, Julius A. Stratton Professor in Electrical Engineering and Physics
  • May 19, 2021
    Hoi Chun “Adrian” Po, 2018-2021 Pappalardo Fellow
    (Theoretical Condensed Matter Physics)
    “Topology at the Corner of the Table”
    Introductory remarks: Liang Fu, Lawrence C. (1944) and Sarah W. Biedenharn Career Development Associate Professor of Physics
  • Prof. Jeff Gore, Latham Family Career Development Assistant Professor of Physics
    Introductory Remarks
  • Dr. Taritree Wongjirad, 2014–17 Pappalardo Fellow
    (Experimental Nuclear and Particle Physics)
    “Searching for Neutrino-less Double Beta Decay Using Quantum Dot Nanoparticles”
  • Dr. Inti Sodemann, 2014–17 Pappalardo Fellow
    (Hard Condensed Matter Theory)
    “The Nature of Spin Superfluidity and its Potential Uses”
  • Dr. Meng Su,  2012–15 Pappalardo Fellow
    (Theoretical Astrophysics)
    “From Space to the Tibet Plateau: Probing the Mystery of the Universe in Gamma Ray and Microwave”
  • Dr. Benjamin Safdi, 2014–17 Pappalardo Fellow
    (Theoretical High Energy Physics)
    “Directional Antineutrino Detection”
  • Dr. Yoav Lahini,  2012–15 Pappalardo Fellow
    (Experimental Soft Condensed Matter & Biophysics)
    “Towards Optical Measurements of Virus Self-Assembly: How Does a Virus Grow?“
  • Prof. Peter Fisher, Head, Department of Physics
    Introductory Remarks
  • Dr. Robert Penna, 2013–16 Pappalardo Fellow
    (Theoretical Astrophysics)
    “Spinning Black Holes”
  • Dr. Jeongwan Haah, 2013–16 Pappalardo Fellow
    (Quantum Information Theory)
    “Protecting Quantum Information”
  • Dr. Inna Vishik,  2013–16 Pappalardo Fellow
    (Experimental Condensed Matter)
    “Adventures in Unconventional Superconductivity”
  • Dr. Guy Bunin, 2013–16 Pappalardo Fellow
    (Biophysics & Non-equilibrium Statistical Mechanics)
    “From Symmetries to Probabilities”
  • Dr. Joshua Spitz,  2011–14 Pappalardo Fellow
    (Experimental Nuclear and Particle Physics)
    “Testing Einstein with Neutrinos”
  • Prof. Marin Soljačić, 2008 MacArthur Fellow; 2000-03 Pappalardo Fellow
    (Condensed Matter Theory)
    Introductory Remarks
  • Dr. David Hsieh, 2009–12 Pappalardo Fellow
    (Condensed Matter Experiment)
    “A New Generation of Insulators for the Electronics Future”
  • Dr. Paul Chesler, 2009–12 Pappalardo Fellow
    (Nuclear & Particle Theory)
    “Applied String Theory: from Gravitational Collapse to Heavy Ion Collisions”
  • Dr. Paola Rebusco, 2007–10 Pappalardo Fellow
    (Theoretical Astrophysics)
    “Astronomers-to-be at MIT”
  • Dr. Yusuke Nishida, 2008–11 Pappalardo Fellow
    (Nuclear & Particle Theory)
    “Universal Physics with Ultracold Atoms”
  • Dr. Jeff Gore, 2007–10 Pappalardo Fellow
    (Biophysics)
    “Is Evolution Reversible?”
  • Prof. Ed Bertschinger, Professor of Physics and Former Head, Department of Physics
    Introductory Remarks
  • Dr. David Tong, 2001-2004 Pappalardo Fellow
    (String Theory)
    “Is String Theory Right or is It Just Useful?”
  • Dr. Robert Simcoe, 2003-2006 Pappalardo Fellow
    (Experimental Astrophysics)
    “Playing with FIRE: The Edge of the Universe as seen from Magellan”
  • Dr. Jocelyn Monroe, 2006-2009 Pappalardo Fellow
    (Dark Matter and Neutrino Physics)
    “Particle Physics at the Dark Frontier”
  • Dr. Michael Fogler, 2000-2003 Pappalardo Fellow
    (Condensed Matter Theory)
    “Graphene Twist and Rock-n-Roll”
  • Dr. Henriette Elvang, 2005-2008 Pappalardo Fellow
    (String Theory)
    “Recent Advances in Amplitude Calculations and Their Applications”