Current Seminars and Colloquia

PHYSICS Colloquium

February 25 2021, Thursday, 3:30 pm CST

Via Zoom (contact Physics Dept. for link) 

Dr. Ajit Srivastava   

PHYSICS Colloquium

February 18 2021, Thursday, 3:30 pm CST

Via Zoom (contact Physics Dept. for link) 

Dr. Joe Smerdon

PHYSICS Colloquium

February 11 2021, Thursday, 3:30 pm CST

Via Zoom (contact Physics Dept. for link) 

Dr. Yue Cao

Argonne National Lab

‘Normal-state’ nematicity in a spin-orbit coupled Mott insulator

Nematicity – unidirectional order that breaks the rotation symmetry of the underlying lattice – appears to be ubiquitous among different families of high Tc cuprates and Fe-based superconductors. All known cases involve metallic materials or doped Mott insulators, i.e. systems with itinerant carriers, leading to theoretical descriptions centering around the Fermi surface topology. Here we discuss nematic order in the spin-orbit-coupled Mott insulator Sr2IrO4. The transverse charge susceptibility is two-fold symmetric relative to the Ir-O-Ir bond direction at room temperature above the Neel antiferromagnetic order. Close structural surveys using electron, neutron and X-ray diffraction and phonon measurements using inelastic X-ray scattering show the lattice maintains tetragonal symmetry within our experimental resolution, suggesting an electronic origin of the newly observed order. The nematicity and the lattice degree of freedom both exhibit an anomaly around the onset of the long-range magnetism, highlight the orbital and charge nature of the pseudospin, as well as the intricate interaction between the quasi-2D magnetic layers. We will discuss the implications of our discovery, both in the realm of iridates and more broadly regarding doped Mott insulators. 

PHYSICS Colloquium

February 4 2021, Thursday, 3:30 pm CST

Via Zoom (contact Physics Dept. for link) 

Dr. Harry Ruda

PHYSICS Colloquium

January 28 2021, Thursday, 3:30 pm CST

Via Zoom (contact Physics Dept. for link) 

Dr. Sunil Chirayath   

PHYSICS Colloquium

January 21 2021, Thursday, 4:00 pm CST

Via Zoom (contact Physics Dept. for link)

Dr. Adina Luican-Mayer 
University of Ottawa

Quantum materials at the atomic scale

Understanding and controlling the properties of 2D materials to our advantage can be contemplated with the development of experimental tools to probe and manipulate electrons and their interactions at the atomic scale. In this talk, I will present scanning tunnelling microscopy and spectroscopy experiments aimed at: elucidating the nature of atomic-scale defects in 2D materials [1], visualizing moiré patterns between crystals with different symmetries [2] and imaging surface and edge states in a magnetic topological system. Moreover, I will discuss how we leverage our expertise in probing and engineering electronic states at surfaces of 2D materials to further the development of graphene-based gas sensors [3] and gated quantum dot circuits based on 2D semiconductors [4]. 

[1] Plumadore et al., PRB, (2020) 
[2] Plumadore et al., Journal of Applied Physics, (2020)
[3] Rautela et al., ACS Applied Materials & Interfaces (2020) ​
[4] Boddison-Chouinard, Appl. Phys. Lett., (2019)

HEP Seminar

January 21 2021, Thursday, 12:00 pm CST
More details: osuhep.okstate.edu   

Roshan Mammen Abraham

Oklahoma State University

NC Neutrino interactions at FASERnu

OKPVRI Annual Meeting & Symposium

January 15 2021
https://okpvri.okstate.edu