Seeing the gravitational wave universe
Physics Professor Chiara M. F. Mingarelli’s and graduate student J. Andrew Casey-Clyde’s “Perspective” just published in Science
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Upcoming visit by Dr. Sylvester James Gates
The University of Connecticut Department of Physics is pleased to announce the upcoming colloquium by Dr. Sylvester James Gates Jr. on November 18th in Gant West 002 from 3:30-4:45PM. Dr. Gates is a theoretical high-energy physicist who has made significant, pioneering contributions to supersymmetry, supergravity, and superstring theory. His colloquium will concern the ongoing efforts to […]
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UConn Physics welcomes two new faculty in quantum science
This year, the Department of Physics proudly welcomes two new faculty members – Lea Ferreira dos Santos and Pavel Volkov […]
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Prof. Jain organized International Workshop on Oxide Electronics
Associate Professor of Physics and Institute of Materials Science Menka Jain recently organized the 28th International Workshop on Oxide Electronics, 2-5th October, Portland, Maine. Other co-organizers were Charles H. Ahn (Yale University), Divine Kumah (North Carolina State University), and Ryan Comes (Auburn University). There were close to 150 attendees from all around the world. The […]
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Prof. Mingarelli is the runner up of Inspiring Women in Science awards
Prof. Chiara Mingarelli is the Inspiring Women in Science awards 2022 Scientific Achievement Runner-Up. The Inspiring Women in Science awards celebrate and support the achievements of women in science, and all those who work to encourage girls and young women to engage with STEM subjects and stay in STEM careers around the world. For more […]
[Read More]Recent Events
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Dr. Shane P. Kelly, Johannes Gutenberg University Mainz, "Dynamical phases of resonant light-matter interactions in cavity QED", Atomic, Molecular, and Optical Physics Seminar3:30pm
12/5
Dr. Shane P. Kelly, Johannes Gutenberg University Mainz, "Dynamical phases of resonant light-matter interactions in cavity QED", Atomic, Molecular, and Optical Physics Seminar
Monday, December 5th, 2022
03:30 PM - 04:30 PM
Storrs Campus GS-119
Dr. Shane P. Kelly, Johannes Gutenberg University Mainz
Dynamical phases of resonant light-matter interactions in cavity QED
We consider the dynamical phases occurring when multi-level atoms couple to the photonic modes of an electromagnetic cavity. We first present how, in cavities far detuned from atomic frequencies, the cavity modes mediate effective interactions between atoms. In this limit, we consider three examples, one in which the interactions mediate spin glass physics, a second in which they simulate the BCS model of superfluidity, and a third where the cavity mediates a multi-level spin exchange interaction. We discuss a unifying framework to predict the resulting dynamical phases in these three examples and then discuss the effect of tuning the cavity in resonance. In the resonant limit, all three examples show qualitatively different physics. The spins in the spin glass hybridize with the photons and modify the universal form of the slow relaxation, realizing what we interpret as a photon-spin glass. While in the examples of the superfluid simulator and multi-level spin exchange interactions, we show an enhancement of superfluid/magnetic order occurs when the cavity is tune on resonance. These results pave the wave for understanding the dynamical phase of emerging many body cavity QED experiments. -
Profs. Erin Scanlon, Xian Wu, and Matt Guthrie, Department of Physics, University of Connecticut , "An Introduction to Physics Education Research", Profs. Erin Scanlon, Matt Guthrie, Xian Wu (UConn Physics Colloquium)3:30pm
12/2
Profs. Erin Scanlon, Xian Wu, and Matt Guthrie, Department of Physics, University of Connecticut , "An Introduction to Physics Education Research", Profs. Erin Scanlon, Matt Guthrie, Xian Wu (UConn Physics Colloquium)
Friday, December 2nd, 2022
03:30 PM - 04:30 PM
Storrs Campus GW-002
Profs. Erin Scanlon, Xian Wu, and Matt Guthrie, Department of Physics, University of Connecticut
An Introduction to Physics Education Research -
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut, "Physical processes behind the emergence of superposition fringes", Graduate Student Seminar12:15pm
12/2
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut, "Physical processes behind the emergence of superposition fringes", Graduate Student Seminar
Friday, December 2nd, 2022
12:15 PM - 01:15 PM
Storrs Campus GS-119
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut
Physical processes behind the emergence of superposition fringes
This year's Nobel Prize[1] in Physics went to three physicists for demonstrating "Quantum Entanglement" as a "spooky action at a distance", a unique quantum phenomenon. For their experimental demonstrations, they used mostly 2-beam Mach-Zehnder Interferometer (MZI), originally invented in 1892 for precision measurements.
In the first segment of this talk, I will describe several MZI experiments [2-4], which I have carried out, with my personal intention to understand and visualize the invisible physical interaction processes, which generate the superposition fringes, under different conditions. In all cases, it was clear that the mathematical Superposition Principle (SP) models the first step of joint amplitude stimulation of the dipoles (detector) by the two superposed Evectors. The different amplitudes, phases, polarizations, and the Poynting vectors are correctly represented by the math.
The mathematical correctness and the physical reality of the two time- and space-evolving distinct signals should not be assigned to a single stable entity.
In the second segment of the talk, I will define "Entanglement" as an interaction process-driven phenomenon between entities susceptible to energy exchange, guided by some mutually compatible force of interaction. This avoids the objection of "spooky action at a distance". In reality, everything in this cosmic universe is entangled by the two long-range forces, Gravity, and Electromagnetism. In the very short range, interactions are guided by the two short-range forces -- strong and weak nuclear forces. In spite of these short and long-range driven entanglements all around the cosmic system, we have learned to construct clever instruments that are capable of measuring various phenomena and forces as only local effects with sufficient accuracies to support our evolving theories.
1. Nature Photonics Editorial, "Celebrating entanglement" https://doi.org/10.1038/s41566-022-01122-8 ; Nov.28, 2022.
2. C. Roychoudhuri, "Differentiating the Superposition Principle from the Measurable Superposition Effects in Interferometry", https://www.intechopen.com/books/interferometry-recent-developments-and-contemporaryapplications/differentiating-the-superposition-principle-from-the-measurable-superposition-effects-in-interferome
3. C. Roychoudhuri & A. M. Barootkoob, "Generalized quantitative approach to two-beam fringe visibility (coherence) with different polarizations and frequencies"; SPIE Conf. http://Proc.Vol.7063, paper #4 (2008 Annual Conference). Access from my website; paper # "2008.5": http://www.natureoflight.org/CP/
4. C. Roychoudhuri, "The Locality of the Superposition Principle Is Dictated by Detection Processes", Physics Essays, V.19, No.3 (2006). Access from my website; paper # "2006.1": http://www.natur -
Dr. Avadh Saxena, Los Alamos National Lab , "Hopfions in Condensed Matter: Anisotropic Heisenberg Magnets", Condensed Matter Physics Seminar2:30pm
11/30
Dr. Avadh Saxena, Los Alamos National Lab , "Hopfions in Condensed Matter: Anisotropic Heisenberg Magnets", Condensed Matter Physics Seminar
Wednesday, November 30th, 2022
02:30 PM - 03:30 PM
Storrs Campus GS-117
Dr. Avadh Saxena, Los Alamos National Lab
Hopfions in Condensed Matter: Anisotropic Heisenberg Magnets
Nontrivial topological defects such as knotted solitons called hopfions have been observed in a variety of materials including chiral magnets, nematic liquid crystals and even in ferroelectrics as well as studied in other physical contexts such as Bose-Einstein condensates. These topological entities can be modeled using the relevant physical variable, e.g., magnetization, polarization or the director field. Specifically, we find exact static soliton solutions for the unit spin vector field
of an inhomogeneous, anisotropic three-dimensional (3D) Heisenberg ferromagnet and calculate the corresponding Hopf invariant H analytically and obtain an integer, demonstrating that these
solitons are indeed hopfions [1]. H is a product of two integers, the first being the usual winding number of a skyrmion in two dimensions, while the second encodes the periodicity in the third dimension. We also study the underlying geometry of H, by mapping the 3D unit vector field to tangent vectors of three appropriately defined space curves. Our analysis shows that a certain intrinsic twist is necessary to yield a nontrivial topological invariant (linking number). Finally, we focus on the formation energy of hopfions to study their properties for potential applications.
[1] R. Balakrishnan, R. Dandoloff, and A. Saxena, arXiv:2202.07195 -
Graduate student Jonathan Smucker, Department of Physics, University of Connecticut , "Modeling a New Type of Charge Transfer in C60 Collisions", Atomic, Molecular, and Optical Physics Seminar3:30pm
11/28
Graduate student Jonathan Smucker, Department of Physics, University of Connecticut , "Modeling a New Type of Charge Transfer in C60 Collisions", Atomic, Molecular, and Optical Physics Seminar
Monday, November 28th, 2022
03:30 PM - 04:30 PM
Storrs Campus GS-119
Graduate student Jonathan Smucker, Department of Physics, University of Connecticut
Modeling a New Type of Charge Transfer in C60 Collisions
Charge transfer in ion-atom collisions has been studied for decades due to its many applications to plasma physics, astrophysics, and atmospheric sciences. Recently, studies are being conducted examining charge transfer with more complex targets. These more complex systems create a slew of complications that allow for new types of charge transfer collisions. Of particular importance is the effect chemistry can have on these reactions. We propose a new type of charge transfer in collisions between C60 and its positively charged ion. Quantum molecular dynamics simulations indicate that under certain conditions the two C60 molecules will temporarily bond forming "dumbbell" shaped C120 molecules. These bonds between molecules allow for the efficient transfer of the charge. We compare our proposed model to existing experimental data. This is the first theoretical model developed to describe large scattering angle charge transfer cross sections in C60 + C60+ collisions. -
Dr. Sylvester James Gates, University of Maryland, "Seeking Group Theory Mathematics For SUSY", Dr. Sylvester James Gates (UConn Physics Colloquium)3:30pm
11/18
Dr. Sylvester James Gates, University of Maryland, "Seeking Group Theory Mathematics For SUSY", Dr. Sylvester James Gates (UConn Physics Colloquium)
Friday, November 18th, 2022
03:30 PM - 04:30 PM
Storrs Campus GW-002
Dr. Sylvester James Gates, University of Maryland
Seeking Group Theory Mathematics For SUSY
Concepts in the mathematics of group theory (roots, weights, raising and lowering operators) lie at the foundation of the physics described in the Standard Model. A similar foundation for supersymmetry (SUSY) is currently lacking. Efforts to construct it are reviewed.
Speaker's bio: Prof. Gates received Bachelor of Science degrees in both physics and mathematics and a Ph.D. in physics from MIT. At the University of Maryland, he became the first African American to hold an endowed chair in physics at a major U.S. research university. Gates is the past president of the American Physical Society (APS), a role to which he was elected in 2019. He has received numerous awards and accolades, including the 2013 Mendel Medal and the 2013 National Medal of Science from former President Barack Obama. In 2013, he was also elected to the National Academy of Sciences, becoming its first African American theoretical physicist recognized in its 150 year-old history. He also served on former President Barack Obama's Council of Advisors on Science and Technology. In addition, Gates has just been named as the 2023 recipient of the prestigious Hans Christian Oersted Medal, presented by the AAPT in honor of his outstanding leadership and impact in physics education.
Flier for the presentation: https://physics.uconn.edu/wp-content/uploads/sites/2234/2022/11/gates_flyer_final.pdf -
Graduate Student Jamie Shaw, Department of Physics, University of Connecticut, "Prospects for Laser Cooling and Trapping Aluminum Monochloride", PhD Dissertation Defense10:00am
11/18
Graduate Student Jamie Shaw, Department of Physics, University of Connecticut, "Prospects for Laser Cooling and Trapping Aluminum Monochloride", PhD Dissertation Defense
Friday, November 18th, 2022
10:00 AM - 12:00 PM
Storrs Campus GS-119
Graduate Student Jamie Shaw, Department of Physics, University of Connecticut
Prospects for Laser Cooling and Trapping Aluminum Monochloride
The advent of laser cooling has ushered in a platform for studying light-matter interactions with unprecedented control. Over the last 20 years, the techniques in laser cooling have become refined enough to enable specific diatomic and polyatomic molecules to be directly laser cooled into the ultracold regime. In this dissertation talk, I will introduce a diatomic species new to the field of laser cooling which promises many advantages over those used in current experiments. Using three novel, high power, UV laser systems developed for this purpose, I will provide initial probes of the molecular structure critical for laser cooling and demonstrate the first signs of optical forces through radiative deflection of a molecular beam.
Webex URL: https://uconn-cmr.webex.com/meet/dam17012 -
Dr. Priya Sharma, University of Connecticut, "Impurity/Confinement Induced Anomalous Thermal Hall Effect in Chiral Phases of Superfluid 3He ", Condensed Matter Physics Seminar2:00pm
11/16
Dr. Priya Sharma, University of Connecticut, "Impurity/Confinement Induced Anomalous Thermal Hall Effect in Chiral Phases of Superfluid 3He ", Condensed Matter Physics Seminar
Wednesday, November 16th, 2022
02:00 PM - 03:00 PM
Storrs Campus GS-117
Dr. Priya Sharma, University of Connecticut
Impurity/Confinement Induced Anomalous Thermal Hall Effect in Chiral Phases of Superfluid 3He
Abstract :
I will discuss superfluid 3He as a quantum material that can be studied to deepen the broad understanding of quantum condensed matter. Starting with an introduction to this p-wave ordered spin-triplet system and its rich phase diagram, I will motivate the investigation of the superfluid phases under the influence of disorder and confinement. I will describe calculations of an anomalous thermal Hall effect (ATHE) induced by impurities and/or confinement in a chiral phase of superfluid 3He. The ATHE provides an important tool to identify signatures of broken time-reversal and mirror symmetries and topology in chiral superconductors/superfluids. I will conclude with a brief outlook and by connecting to recent work.