Seminar "Magnetic Field Induced Competing Phases in Kitaev Magnets" by Dr. Ryui Kaneko

Speaker : Dr. Ryui Kaneko from Institute for Solid State Physics, University of Tokyo

[Profile of Speaker]

Apr. 2017 - present: Postdoctoral Researcher, Institute for Solid State Physics, University of Tokyo

Oct. 2016 - Mar. 2017: Postdoctoral Researcher, WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science

Jun. 2014 - Aug. 2016: Postdoctoral Researcher, Institut fuer Theoretische Physik, Goethe-Universitaet Frankfurt

Apr. 2014 - May 2014: Postdoctoral Researcher, Department of Applied Physics, University of Tokyo

Mar. 2014: Ph.D. in Engineering, Department of Applied Physics, University of Tokyo

[Abstract]

The Kitaev candidate material α-RuCl3 has attracted much interest recently because of the field-induced spin liquid. Motivated by the experimental findings, we investigate a phase diagram of the extended Kitaev model on a honeycomb lattice, where the Kitaev and off-diagonal spin-exchange interactions compete.
We first examine the ground states of the classical model by the simulated annealing method to get an insight into the phase diagram. We find various magnetic orders with substantially large unit cells.
Based on the findings in the classical model, we study the quantum model by applying the two-dimensional tensor-network method. When the field and the off-diagonal exchange interaction are sufficiently large, we find two intermediate phases, sandwiched by the ferromagnetic and zigzag phases. They become nonmagnetic as the field decreases and spontaneously break the lattice rotational symmetry.