UConn seismometer detects Puerto Rico event
The Geophysics research group (Prof. Vernon Cormier and students) operate a seismic wave station that continuously monitors vibrations in the earth’s crust, many of which arise from seismic events that happen far away. These waves travel through the deep earth, and eventually make their way to the surface where they are detected. The above […]
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Professor Donna Strickland , Katzenstein Distinguished Lecturer, March 13, 2020
The University of Connecticut, Department of Physics, is proud to announce that on March 13, 2020, Professor Donna Strickland of the Department of Physics and Astronomy at the University of Waterloo will be presenting the 2020 Distinguished Katzenstein Lecture. Prof. Strickland is one of the recipients of the 2018 Nobel Prize in Physics for developing […]
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Insight from APS: Careers in Physics
What is a Bachelors of Science degree in Physics good for? What kinds of jobs are available to graduates who complete a 4-year degree in physics, but decide not to pursue an advanced degree? How does a physics degree stack up against other STEM fields in terms of employment options in today’s highly competitive job […]
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Ron Mallett Featured on NBC Connecticut
Could traveling into the past be part of our future? Quite possibly, says Ron Mallett, a UConn emeritus professor of physics who has studied the concept of time travel for decades. Earlier this month, he spoke with NBC Connecticut reporter Kevin Nathan about his life and work as a theoretical physicist, and discussed how time […]
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UConn Today: A New Phase for the Gant Science Complex
The UConn Today published an article highlighting the state of 10-year renovation of the Gant Science Complex. The Complex was first constructed between 1974 and 1978 and was home to the departments of mathematics and physics for several decades. The renovation to this 285,00 square-foot campus landmark is part of Next Generation Connecticut, the initiative […]
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Dr. Kiryl Pakrouski, Department of Physics, Princeton University, "Automatic design of Hamiltonians", Condensed Matter Physics Seminar2:00pm
1/10
Dr. Kiryl Pakrouski, Department of Physics, Princeton University, "Automatic design of Hamiltonians", Condensed Matter Physics Seminar
Friday, January 10th, 2020
02:00 PM - 03:00 PM
Storrs Campus GS 119
Dr. Kiryl Pakrouski, Department of Physics, Princeton University
Automatic design of Hamiltonians
We formulate an optimization problem of finding optimal Hamiltonians by analogy to the variational principle. Given a variational ansatz for a Hamiltonian we construct a loss function as a weighted sum of relevant Hamiltonian properties specifying thereby the search query. Using fractional quantum Hall effect as a test system we illustrate how the framework can be used to determine a generating Hamiltonian of a finite-size model wavefunction (Moore-Read Pfaffian and Read-Rezayi states) or to find optimal parameters for an experiment. We also discuss how the search for approximate generating Hamiltonians may be used to find simpler and more realistic models implementing the given exotic phase of matter by experimentally accessible interaction terms. -
Dr. GiBaik Sim, Department of Physics, Korea Advanced Institute of Science and Technology, "Interacting spin-3/2 and spin-1 Fermions : Topological superconductivity", Condensed Matter Physics Seminar2:00pm
1/7
Dr. GiBaik Sim, Department of Physics, Korea Advanced Institute of Science and Technology, "Interacting spin-3/2 and spin-1 Fermions : Topological superconductivity", Condensed Matter Physics Seminar
Tuesday, January 7th, 2020
02:00 PM - 03:00 PM
Storrs Campus GS 119
Dr. GiBaik Sim, Department of Physics, Korea Advanced Institute of Science and Technology
Interacting spin-3/2 and spin-1 Fermions : Topological superconductivity
In this talk, I will first discuss generic realization of topological superconductivity in three-dimensional quadratic band touching system. [1]
Based on the interacting Luttinger model, I exhibit that the absence of particle-hole symmetry leads the system to favor the special spin-quintet
superconductors with secondary spin-singlet pairing ; (i) uniaxial nematic phase with secondary spin-singlet pairing \( \left(S_{3z^2-r^2}+s\right)\), (ii) timereversal breaking phase with secondary spin-singlet pairing \( \left( S_{3z^2 -r^2} + S_{xy}+iS_{x^2-y^2} + s \right) \). \( \left(S_{3z^2-r^2}+s\right)\) phase possesses topologically non-trivial nodal rings and drumhead-like surface states. \( \left( S_{3z^2 -r^2} + S_{xy}+iS_{x^2-y^2} + s \right) \) phase contains topologically protected Bogoliubov Fermi pockets and corresponding zero-energy arc states. I will also argue
possible applications of this theory to YPtBi.
As a next step, I will introduce the spin-triplet superconductivity in the
newly discovered form of the topological semimetal, where spin-1 electrons
form triple-band crossings. [2] The peculiar property of spin-1 Fermions is that Fermi statistics rules out on-site spin-singlet pairing. Adopting the Landau theory of spin-triplet pairings, I exhibit that the system stabilizes two
distinct phases ; (i) time-reversal symmetric \(S_z\) phase, (ii) time-reversal breaking \(S_{x}+iS_{y}\) phase. Remarkably, both of these phases have gapless Bogoliubov quasiparticles and furthermore possess topological invariants for each nodal ring or Bogoliubov Fermi surface.
[1] G. Sim, A. Mishra, M. J. Park, Y. B. Kim, G. Y. Cho, and S. Lee, Physical Review B 100, 064509 (2019).
[2] G. Sim, M. J. Park, and S. Lee, arXiv:1909.04015 (2019). -
Dr. Julia Wildeboer, Max Planck Institute for the Physics of complex systems, "Tales from the Quantum Spin Liquid Crypt", Condensed Matter Physics Seminar4:00pm
12/12
Dr. Julia Wildeboer, Max Planck Institute for the Physics of complex systems, "Tales from the Quantum Spin Liquid Crypt", Condensed Matter Physics Seminar
Thursday, December 12th, 2019
04:00 PM - 05:00 PM
Storrs Campus GS-117
Dr. Julia Wildeboer, Max Planck Institute for the Physics of complex systems
Tales from the Quantum Spin Liquid Crypt
Two-dimensional frustrated quantum antiferromagnets can harbor a phase of matter called a quantum spin liquid .This state exhibits no conventional symmetry but emergent, topological order. Remarkably, the spin liquid state has fascinating features such as gapped fractionalized quasiparticle excitations with exotic quantum statistics making it a highly sought after state in the (topological) quantum computation community.
In this talk, I will review properties of a spin liquid state and discuss the concept of quantum entanglement which is an important diagnostic tool when it comes to uncovering the nature of a spin liquid state. I will introduce a family of fractional quantum Hall (FQH) lattice states. Using the Moore-Read lattice state as an example, I will demonstrate how ''FQH physics in lattice systems'' can advance the field by discussing the issue of inserting quasiholes and quasielectrons into the FQH lattice state, the insertion of the latter being impossible in continuum FQH states because of a singularity problem. -
Prof. A. Polkovnikov, Department of Physics, Boston University, "Periodically driven quantum systems", Condensed Matter Physics Seminar2:00pm
12/12
Prof. A. Polkovnikov, Department of Physics, Boston University, "Periodically driven quantum systems", Condensed Matter Physics Seminar
Thursday, December 12th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS-117
Prof. A. Polkovnikov,
Department of Physics,
Boston University
Periodically driven quantum systems
In this talk I will give an overview of periodically driven (Floquet) quantum systems. In particular, after giving a general introduction I will discuss basic ideas of Floquet engineering, relation between the high frequency expansion and the Schrieffer-Wolff transformation, general questions of adiabaticity in such systems, heating and the ways to suppress it. -
Graduate Student Cheng Tu, Department of Physics, University of Connecticut, "Study HVP and HLbL contribution to the muon g - 2 using Lattice QCD ", PhD Dissertation Defense3:00pm
12/10
Graduate Student Cheng Tu, Department of Physics, University of Connecticut, "Study HVP and HLbL contribution to the muon g - 2 using Lattice QCD ", PhD Dissertation Defense
Tuesday, December 10th, 2019
03:00 PM - 05:00 PM
Storrs Campus GS-117
Graduate Student Cheng Tu,
Department of Physics,
University of Connecticut
Study HVP and HLbL contribution to the muon g - 2 using Lattice QCD
The hadronic vacuum polarization (HVP) contribution and long-distance hadronic light-by-light (HLbL) scattering contribution to the muon anomalous magnetic moment are evaluated by using lattice QCD. The HVP calculations are performed with 2 + 1 + 1 flavors of HISQ fermions at the physical pion mass from three ensembles, generated by the MILC collaboration. In the long-distance part of the HLbL contribution, we replace the QCD, four-current connected Green's function from previous HLbL study with the product of two independent πγγ amplitudes, which are joined by an analytic, position space pion propagator. The calculations are performed with near physical pion mass on four different lattice ensembles, which are generated by RBC/UKQCD Collaboration. -
Dr. Adrian Gozar, Applied Physics Department, Yale University , "Optical nano-imaging of novel quantum materials and hetero-structures.", Condensed Matter Physics Seminar2:00pm
12/10
Dr. Adrian Gozar, Applied Physics Department, Yale University , "Optical nano-imaging of novel quantum materials and hetero-structures.", Condensed Matter Physics Seminar
Tuesday, December 10th, 2019
02:00 PM - 03:00 PM
Storrs Campus GS 117
Dr. Adrian Gozar, Applied Physics Department, Yale University
Optical nano-imaging of novel quantum materials and hetero-structures.
'Quantum materials' are platforms for observation of quantum effects at macroscopic scales. Their properties can be often combined in layered structures and are strongly sensitive to external stimuli, suggesting a plausible path towards a new generation of devices with 'on-demand' functionalities. We focus on expanding the material phase-space of these materials and also on finding new ways to probe their surface and interface properties. An example of novel graphitic structures produced in our lab is borophene, a 2D boron allotrope with potential technological uses in flexible electronics and as a precursor to metallic nanotubes. I will discuss synthesis and characterization of large area, up to 100 μm2 in size, single-crystals of borophene on copper surfaces and also ideas for device integration. Scanning near-field optical microscopy (SNOM) is able to probe electronic properties of surface or subsurface crystalline layers despite the presence of underlying metallic substrates. I will illustrate how the lateral and depth resolution are key advantages of SNOM as a non-invasive optical method for device characterization. I will also emphasize the power of this technique for obtaining fundamental information about electron dynamics in hetero-structures. An example is the generation and coupling to novel excitations such as surface Josephson plasma modes in an ultra-thin superconducting film. These results highlight SNOM as a non-invasive tool which is particularly useful for studying interface electron dynamics, imaging states with broken symmetry in correlated systems and topological materials as well as for probing structure, dielectric properties and emergent conduction channels in nano-structures and biological samples. -
Cancelled!, Prof. I. Sochnikov, Department of Physics, University of Connecticut, Cancelled: Graduate Student Seminar12:15pm
12/6
Cancelled!, Prof. I. Sochnikov, Department of Physics, University of Connecticut, Cancelled: Graduate Student Seminar
Friday, December 6th, 2019
12:15 PM - 01:15 PM
Storrs Campus GS-119
Cancelled!
Prof. I. Sochnikov, Department of Physics, University of Connecticut
Quantum sensing and imaging of materials
I will describe our recent discoveries of fascinating emergent phenomena in several quantum materials, including high temperature and low temperature superconductors. I will provide details of our state-of-the-art experimental systems with a focus on quantum sensing and mesoscopic imaging.
Additionally, I will present my view of what a successful doctorate in experimental physics includes, as well as, what you might expect from our Ph.D. program and how to be successful in it. -
Graduate Student Razib Obaid, Department of Physics, University of Connecticut, "Single and multi-photon induced ionization in atoms and molecules", PhD Dissertation Defense10:00am
12/5
Graduate Student Razib Obaid, Department of Physics, University of Connecticut, "Single and multi-photon induced ionization in atoms and molecules", PhD Dissertation Defense
Thursday, December 5th, 2019
10:00 AM - 12:00 PM
Storrs Campus GS-117
Graduate Student Razib Obaid,
Department of Physics,
University of Connecticut
Single and multi-photon induced ionization in atoms and molecules
The response of atomic and molecular species to photoionization is being studied for decades now. These atoms and molecules respond characteristically upon absorption of photons. The interesting question is: how is the energy deposited into the atoms and molecules by absorption of photons ultimately dissipated? The advent and development of X-ray synchrotrons, free-electron lasers and the strong field optical lasers keep ushering new dimensions into this question in terms of the ability of following rapid sequence of events, and, otherwise, identifying hidden relaxation mechanisms.
Through the means of resonant excitation of valence and inner shell electrons of simple atom, such as neon, and cluster-like complex molecular system such as fullerene and endohedral fullerene, we investigated their relaxation mechanisms by absorption of single and multiple photons. At excitation above their characteristic resonances, we observed hitherto unknown time delayed relaxation mechanisms in the structural change of fullerene, interatomic Coulombic decay and incomplete charge transfer processes in endohedral fullerene, and two photon absorption in neon through observation of fluorescence. Furthermore, we also investigated the fragmentation and hydrogen migration dynamics in hydrocarbons to explore the energy dissipation question for biologically relevant systems. The work is worthwhile in that it contributes to the understanding of the ultrafast intrinsic dynamics of various processes and systems relevant to physics, chemistry, and biology.