Astronomer Jonathan Trump interviewed on UConn 360
UConn Astrophysicist and observational astronomer Jonathan Trump was a recent guest on UConn 360, a podcast from the Storrs campus of the University of Connecticut. In this conversation, Jonathan tells about how attending a lecture as an undergraduate at Penn State captured his interest and changed the course of his professional career. Now Jonathan offers […]
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Greetings from the Department Head
New building, new teaching approach, new people – there is a lot of change and excitement in the air for the Physics Department in 2019. The most obvious change is that physics has moved into a newly renovated building. What most alumni will remember as the Math Building has been taken down to its frame […]
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Breaking Up is Hard To Do (for Electrons in High Temperature Superconductors)
Physicists used to think that superconductivity – electricity flowing without resistance or loss – was an all or nothing phenomenon. But new evidence suggests that it’s not so clear cut, at least in copper oxide superconductors. “If we understood why copper oxide is a superconductor at such high temperatures, we might be able to synthesize a better one”, says UConn physicist Ilya Sochnikov. Sochnikov and his colleagues at Rice University, Brookhaven National Lab and Yale recently figured out part of that puzzle, and they report their results in the latest issue of Nature.
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Daniel McCarron wins NSF Early Career Award
Daniel McCarron, assistant professor of physics, the College of Liberal Arts and Sciences, will receive $645,000 over five years for his work on the development of techniques to trap large groups of molecules and cool them to temperatures near absolute zero. The possible control of molecules at this low temperature provides access to new research applications, such as quantum computers that can leverage the laws of quantum mechanics to outperform classical computers.
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Meet the Researcher: Carlos Trallero
When Carlos Trallero started his academic career in physics, he had no idea he would become a pioneer in a field of research that uses high-power lasers to investigate atomic and molecular physical phenomena. Originally from Cuba, where there isn’t much funding for experimental research, Trallero began his academic career by studying theoretical physics. But as a senior graduate student at Stony Brook University, he got the chance to work in a lab doing experimental work and quickly recognized it was his true passion.
[Read More]Recent Events
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Prof. P. Mannheim and Prof. J. Trump , Physics Colloquium (The 2019 Nobel Prize in Physics)3:30pm
10/18
Prof. P. Mannheim and Prof. J. Trump , Physics Colloquium (The 2019 Nobel Prize in Physics)
Friday, October 18th, 2019
03:30 PM - 04:30 PM
Storrs Campus BPB-131
Prof. P. Mannheim and
Prof. J. Trump
The 2019 Nobel Prize in Physics
The 2019 Nobel Prize in physics was awarded to James Peebles for cosmology, and to Michel Mayor and Didier Queloz for the discovery of exoplanets. This colloquium will describe their work. -
Prof. A. Puckett, Department of Physics, University of Connecticut, "Sub-femtoscale structure of strongly interacting matter from "hard" electron-nucleus collisions", Graduate Student Seminar12:15pm
10/18
Prof. A. Puckett, Department of Physics, University of Connecticut, "Sub-femtoscale structure of strongly interacting matter from "hard" electron-nucleus collisions", Graduate Student Seminar
Friday, October 18th, 2019
12:15 PM - 01:15 PM
Storrs Campus GS-119
Prof. A. Puckett, Department of Physics, University of Connecticut
Sub-femtoscale structure of strongly interacting matter from "hard" electron-nucleus collisions
The emergence of nucleon structure and dynamics from strong interactions among its elementary quark and gluon constituents is one of the most difficult and interesting problems in all of physics. The strong interaction, NOT the electroweak Higgs mechanism, is responsible for the dynamical generation of the mass of approximately 98% of all ordinary matter in the universe. Scattering of ultrarelativistic electron beams from nucleon and nuclear targets is the tool of choice for the precision study of nucleon structure.
The Super BigBite Spectrometer (SBS) at Jefferson Lab, a novel device currently nearing completion, with installation and first beam tentatively scheduled for 2020, will facilitate a focused program of high-impact nucleon structure measurements in electron-nucleon scattering at large momentum transfer. In this talk I will give an overview of the SBS program and opportunities for graduate student involvement. -
Dr. V. Juričić, Nordic Institute for Theoretical Physics, "Higher order topological states: General principle of construction and their realizations", Condensed Matter Physics Seminar2:00pm
10/17
Dr. V. Juričić, Nordic Institute for Theoretical Physics, "Higher order topological states: General principle of construction and their realizations", Condensed Matter Physics Seminar
Thursday, October 17th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS-119
Dr. V. Juričić,
Nordic Institute for Theoretical Physics
Higher order topological states: General principle of construction and their realizations
Topological gapless edge or surface states are protected by the bulk topological invariant and arise as a consequence of the so-called bulk-boundary correspondence, which is a hallmark feature of a topological state. Recently, the notion of topological states of matter has been extended to the so-called higher order topological (HOT) states featuring gapless surface states at boundaries of co-dimension higher than one, such as hinges and corners.
In this talk, I will particularly discuss a general principle of construction for these states within the Dirac Hamiltonian framework [1]. As I will show, if a D-dimensional first-order or regular topological phase involves m Hermitian matrices that anticommute with additional p−1 mutually anticommuting matrices, it is conceivable to realize an nth-order HOT phase, where n=1,...,p, with appropriate combinations of discrete symmetry-breaking Wilsonian masses. This principle will be illustrated on prototypical three-dimensional gapless systems, such as a nodal-loop semimetal possessing SU(2) spin-rotational symmetry, and Dirac semimetals, transforming under (pseudo)spin- 1/2 or 1 representations. The former system permits an unprecedented realization of a fourth-order phase, without any surface zero modes. The crystalline symmetries play an important for HOT states, but, as I will show, they can also be realized in amorphous solids [2]. Particularly, as long as structural disorder is confined by the outer crystalline boundary, the system continues to host corner states, realizing an amorphous HOT insulator. However, as structural disorder percolates to the edges, corner states start to dissolve into amorphous bulk, and ultimately the system becomes a trivial insulator. Finally, I will discuss a realization of an out-of-equilibrium second order topological insulator, which is obtained from a quantum spin Hall insulator by using a rather generic kicking protocol involving a mass that breaks time-reversal and fourfold rotational symmetries [3].
1. D. Calugaru, V. Juričić, and B. Roy, Phys. Rev. B 99, 041301(R) (2019).
2. A. Agarwala, V. Juričić, and B. Roy, B., arXiv:1902.00507.
3. T. Nag, V. Juričić, and B. Roy, arXiv:1904.07247. -
Dr. Jian-Xin Zhu, Los Alamos National Laboratory, "Electronic Structure and Topology in f-Electron Quantum Matter", Condensed Matter Physics Seminar2:00pm
10/15
Dr. Jian-Xin Zhu, Los Alamos National Laboratory, "Electronic Structure and Topology in f-Electron Quantum Matter", Condensed Matter Physics Seminar
Tuesday, October 15th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS-119
Dr. Jian-Xin Zhu, Los Alamos National Laboratory
Electronic Structure and Topology in f-Electron Quantum Matter
In recent years there has been a surge of interest in quantum materials with topologically protected properties, which are robust against disorder effects. Interesting examples are topological insulators and three-dimensional Weyl metals. Electronic structure has played an important role in the exotic properties of these materials. In this talk, I will present our recent theoretical study of electronic structure and its topology in f-electron PuB\({}_4\) [1] and Ce\({}_3\)(Pt,Pd)\({}_3\)Bi\({}_4\) [2] compounds. In addition to uncovering topologically nontrivial electronic states, the role of f-electron and in particular the electronic correlation effects are discussed in the framework of density functional theory and its combination with the dynamical mean-field theory.
[1] H. Choi, W. Zhu, S.K. Cary, L.E. Winter, Z. Huang, R.D. McDonald, V. Mocko, B.L. Scott, P.H. Tobash, J.D. Thompson, S.A. Kozimor, E.D. Bauer, J.-X. Zhu, and F. Ronning, "Experimental and theoretical study of topology and electronic correlations in PuB\({}_4\)", Phys. Rev. B 97, 201114(R) (2018).
[2] C. Cao, G.-X. Zhi, and J.-X. Zhu, "From Trivial Kondo Insulator Ce\({}_3\)Pt\({}_3\)Bi\({}_4\) to Topological Nodal-line Semimetal Ce\({}_3\)Pd\({}_3\)Bi\({}_4\)", arXiv:1904.00675. -
Dr. Masakaki Tomii, Department of Physics, University of Connecticut Non-perturbative matching of Wilson coefficients from four-flavor to three-flavor theories using lattice QCD, Particle, Astrophysics, and Nuclear Physics Seminar2:00pm
10/14
Dr. Masakaki Tomii, Department of Physics, University of Connecticut Non-perturbative matching of Wilson coefficients from four-flavor to three-flavor theories using lattice QCD, Particle, Astrophysics, and Nuclear Physics Seminar
Monday, October 14th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS-413.E
Dr. Masakaki Tomii, Department of Physics, University of Connecticut
Non-perturbative matching of Wilson coefficients from four-flavor to three-flavor theories using lattice QCD
The first lattice result for direct CP violation in \(K \to \pi\pi\) decay in the Standard Model published by RBC/UKQCD in 2015 is desired to be more precise to see the deviation from the experimental value more clearly. In this talk, I will overview RBC/UKQCD's calculation of \(K \to \pi\pi\) matrix elements mentioning a particular error
source: Since RBC/UKQCD calculated the matrix elements with the four-quark operators without the charm quark, we need the
corresponding Wilson coefficients in the three-flavor theory, which can be obtained by converting from the four-flavor theory.
Perturbative matching may result in a significant uncertainty since it
needs to be done below charm threshold. To resolve this problem, we are trying to do this matching in a non-perturbative prescription using lattice QCD. I will explain the strategy of the matching and show some results of an exploratory calculation. -
Dr. Jianwei Qiu, Director, Theory Center, Jefferson Lab, "Nuclear Femtography - A new frontier of science and technology", Physics Colloquium3:30pm
10/11
Dr. Jianwei Qiu, Director, Theory Center, Jefferson Lab, "Nuclear Femtography - A new frontier of science and technology", Physics Colloquium
Friday, October 11th, 2019
03:30 PM - 04:30 PM
Storrs Campus BPB 131
Dr. Jianwei Qiu, Director, Theory Center, Jefferson Lab
Nuclear Femtography - A new frontier of science and technology
The proton and neutron, known as nucleons, are the fundamental building blocks of all atomic nuclei and make up essentially all the visible matter in the universe, including the stars, the planets, and us. Nucleons are not static but have complex internal structure, emerged as strongly interacting and relativistic bound states of quarks and gluons of Quantum Chromodynamics. Both theory and experimental technology have now reached a point where human is capable of exploring the inner structure of nucleons and nuclei at a sub-femtometer without breaking them, which is expected to lead to a new emerging science of nuclear femtography. In this talk, I will demonstrate that as exciting as the nano-science and technology has been for recent years, there must be a quantum transition when we enter the era of femto-science and technology. The newly upgraded CEBAF facility at Jefferson Lab and proposed Electron-Ion Collider to be built in the US will be a pair of complementary and much needed facilities for exploring the nuclear femtography. They are the most powerful tomographic scanners and/or microscopes able to precisely image inner structure of nucleon and nuclei with a sub-femtometer resolution to help address the most compelling unanswered questions about the elementary building blocks of the visible world, and are capable of taking us to the next frontier of the Standard Model of physics. -
Prof. George N. Gibson, High-Intensity Laser Physics Group, Department of Physics, University of Connecticut, "Exploring Extreme Nonlinear Physics and Quantum Molecular Dynamics with High-Intensity Laser Pulses", Graduate Student Seminar12:15pm
10/11
Prof. George N. Gibson, High-Intensity Laser Physics Group, Department of Physics, University of Connecticut, "Exploring Extreme Nonlinear Physics and Quantum Molecular Dynamics with High-Intensity Laser Pulses", Graduate Student Seminar
Friday, October 11th, 2019
12:15 PM - 01:15 PM
Storrs Campus GS-119
Prof. George N. Gibson, High-Intensity Laser Physics Group, Department of Physics, University of Connecticut
Exploring Extreme Nonlinear Physics and Quantum Molecular Dynamics with High-Intensity Laser Pulses
Ultrafast laser systems can now produce ultrashort (attosecond) pulses of light with extremely high intensity (\(10^{22}\) W/\(cm^2\)), as recognized by the 2018 Nobel Prize in Physics. This has opened up a new world in nonlinear physics and may even test the nonlinear polarizability of the vacuum, itself. More immediate applications may include direct imaging of molecular orbitals and ultrafast atomic scale dynamics. -
Philip Engelke, Department of Physics and Astronomy, Johns Hopkins University, "OH as an Alternate Tracer for Molecular Gas", Astronomy Seminar2:00pm
10/9
Philip Engelke, Department of Physics and Astronomy, Johns Hopkins University, "OH as an Alternate Tracer for Molecular Gas", Astronomy Seminar
Wednesday, October 9th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS-119
Philip Engelke,
Department of Physics and Astronomy, Johns Hopkins University
OH as an Alternate Tracer for Molecular Gas
While molecular gas is an important component of the baryonic mass content of galaxies, tracing interstellar molecular H2 gas is complicated by the fact that diffuse, cold H2 is not detectable. In order to study the mass and distribution of molecular gas in galaxies, tracers such as CO are typically used as surrogates. Evidence suggests large reservoirs of undetected "CO-dark" molecular gas. In this work, we explore the use of OH 18 cm transition as an alternate tracer for molecular gas, by performing observational surveys with the Green Bank Telescope. OH appears to be a viable tracer, and reveals molecular gas in places where CO has not been detected. This finding indicates a larger extent and mass of molecular gas in the Galaxy, translating to roughly twice the known mass of H2. I will describe our results for a "blind survey", as well as a study of the W5 star-forming region in comparison to quiescent interstellar regions, and modeling of the volume density in these different regions. We find that CO-dark molecular gas is widespread and predominantly located outside of star-forming regions, the more typical targets of astronomical observation, and occurs in regions of lower volume density gas. I also describe a technique making use of measured differences in OH main line excitation temperatures and modeling to probe physical conditions of molecular gas.