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Colloquium

Abstract for Next Colloquium

April 22, 2019
11:15am in PH1-223
Refreshments in HSCI-224 from 10:45-11:05am

Ni Ni - UCLA

Magnetism, superconductivity and non-trivial topology in quantum materials

New materials are the driving force for technology innovations and our progressive understanding of condensed matter physics. In the last decade, breakthroughs have been made on two material systems: three-dimensional topological materials and high temperature superconductors. For the former, the discovery of bulk materials with non-trivial topology has led to rich new emergent phenomena, including Fermi arc surface state, chiral pumping effect, colossal photovoltaic effect, etc. For the latter, Fe based superconductors were discovered, joining cuprates and becoming the 2nd member in the high-temperature superconductor club.

In this talk, I will present the exciting progress in both directions. I will first show the discovery of a "hydrogen atom" topological nodal line semimetal where two nontrivial bulk bands touch along a line and no trivial bands exist at the Fermi level. Then I will go through how the chemical doping and external pressure tune the competing structural, magnetic and superconducting orders in the newly discovered 112 Fe pnictide superconductors.

Figure above: Crystal structure (Ca, La)FeAs2

The Colloquium is a unique opportunity for students to learn about new developments in physics and what physicists do after they graduate. Hosted by the Department of Physics and Astronomy at California State University Long Beach, the weekly meetings invite guests from universities, research laboratories, and industry to present and discuss current topics in physics. All students are encouraged to attend for a well-rounded experience and training in physics.

Schedule

The following Colloquia are on Mondays at 11:15am in PH1-223 unless otherwise noted.

Date Title Speaker and Affiliation
April 29, 2019 (TBD - Field: Condensed Matter Physics Theory) Rosa di Felice, USC
May 6, 2019 Student Presentations I Students, CSU Long Beach
May 8*, 2019 Student Presentations II Students, CSU Long Beach

*These Special Colloquia fall outside of the regularly scheduled Monday talks.

Previous Colloquia

The following are Colloquia from this semester. The Colloquium Archive has the Colloquia from previous semesters.

Date Title Speaker and Affiliation
April 15, 2019 Sequencing DNA with Single Molecule Electronics Phil Collins UC Irvine
April 8, 2019 Little Pieces of Big Problems (or Electron Microscopy for Computers and Batteries) Chris Regan, UCLA
March 25/27, 2019 Distinguished Lecture: Probing topological protection of Bismuth nanowire hinge states. Sophie Guéron, Laboratoire de Physique des solides, Orsay France
March 18, 2019 Cosmological Neutrinos Kev Abazajian, UC Irvine
March 11, 2019 Towards Rapid Sequencing of Individual DNA Molecules in Graphene Nanogaps Henk Postma, CSU Northridge
March 4, 2019 Innovative Approaches in mm-Wavelength Cosmology: From Inflation to the Epoch of Reionization and Beyond Abigail Crites, Caltech
February 20, 2019 The Anomalous Origin of Polymer Enhanced Oil Recovery Shima Parsa, Harvard
February 18, 2019 Physics of Knots in Stretched DNA Alexander Klotz, MIT
February 13, 2019 Visualizing brain chemistry using optical nanomaterials Jackson Travis Del Bonis-O'Donnell, UC Berkeley
February 11, 2019 Optical Imaging with Super-resolution and Light Sheet Microscopy to Unravel Transient Processes in Live Cells, Tissues and Organisms Per Niklas Hedde, UC Irvine
February 4, 2019 Materials Science, Where Chemistry and Physics Meet Shahab Derakhshan, CSU Long Beach
January 28, 2019 Improving Tests of Quantum Entanglement by using Light from Distant Quasars Jason Gallicchio, Harvey Mudd College

Sponsors

We acknowledge with gratitude donations and support from the following present sponsors:

  • H.E. and H.B. Miller and Family Endowment
  • Benjamin Carter
  • The American Physical Society
  • Anonymous

We also acknowledge with gratitude our past donors: The Forty-Niner Shops, Inc., The Northrop Grumman Foundation, Sandra Dana, Anonymous.

If you wish to support the Colloquium, please contact the colloquium coordinator or the department chair. Thank you!