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!