FY2022 Annual Report

 

Electronic and Quantum Magnetism Unit
Associate Professor Yejun Feng

Abstract

This is the sixth year of the Electronic and Quantum Magnetism Unit at OIST. 

1. Staff & Students

  • Magarita Dronova, Graduate Student 
  • Sandeep Vijayan, Graduate Student 
  • Andrii Yakymenko, Research Intern + Visiting Research Student
  • Minh Anh Nguyen, Research Intern 
  • Diana Katherine Condor Arboleda, Research Intern 
  • Alexander Trushin, Research Intern
  • Scott Cooper, Technical Staff 
  • Yukiko Murabayashi, Administrative Assistant

2. Collaborations

2.1 Synchrotron x-ray magnetic diffraction under high pressure

  • We explore the all-in-all-out antiferromagnetic order in Eu2Ir2O7, using resonant x-ray magnetic diffraction under continous pressure tuning towards a quantum critical point. 
  • Collaborators:
    • Professor Yishu Wang, University of Tennessee - Knoxville
    • Professor Satoru Nakatsuji, University of Tokyo

2.2 Optical Raman scattering at low temperature

  • We used magnon Raman scattering to explore magnetic and lattice modes in Sr2IrO4.
  • Collaborators:
    • Dr. Xiang Li, Caltech
    • Professor David Hsieh, Caltech
    • Professor Thomas Rosenbaum, Caltech 

2.3 Single crystal diffraction refinement

  • We refine both the lattice and magnetic neutron diffraction data of a spinel single crystal ZnFe2O4. 
  • Collaborators:
    • Dr. Zach Morgan, ORNL, USA
    • Dr. Feng Ye, ORNL, USA
    • Dr. Vaclav Patricek, Institute of Physics of the Czech Academy of Sciences, Czech

3. Activities and Findings

3.1 Optical Raman scattering 

Dr. Xiang Li explored the antiferromagnetic state in Sr2IrO4., using optical Raman techniqures. 

3.2 Single crystal growth using high temperature solution technique

Margarita Dronova is leading the effort on single crystal growth of pyrochlore magnets and taking effort on the subsequent charcterization process.  This work is experimentally collaborated with staff scientists at the Spallation Neutron Source at Oak Ridge National Laboratory. 

 

4. Publications

4.1 Journals

Margarita G. Dronova, Feng Ye, Scott E. Cooper, Anjana Krishnadas, Christina M. Hoffmann, Yuita Fujisawa, Yoshinori Okada, Daniel I. Khomskii, Yejun Feng, Controlling inversion disorder in a stoichiometric spinel magnet. Proc. Natl. Acad. Sci. USA, 119, e2208748119 (2022). 

4.2 Books and other one-time publications

Nothing to report

4.3 Oral and Poster Presentations

Invited talks by the PI:

Nothing to report

Contributed talks with the PI listed:

M. G. Dronova, Feng Ye, S. E. Cooper, A. Krishnadas, C. M. Hoffmann, Y. Fujisawa, Y.Okada, D. I. Khomskii, Yejun Feng, 13pW631-11,Defect control in magnetic spinel oxide ZnFe2O4. Japanese Physical Society Autumn Meeting, Tokyo, Sept. 13, 2022. 

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report

6. Meetings and Events

Nothing to report

7. Other

Nothing to report