Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session K24: Spin Liquids Theory and Application to Materials
8:00 AM–11:00 AM,
Wednesday, March 7, 2018
LACC Room: 403A
Sponsoring Units: GMAG DMP
Chair: Gang Chen, Fudan Univ
Abstract: K24.00007 : Thermal Fractionalization in Kitaev Quantum Spin Liquids*
9:12 AM–9:48 AM
The quantum spin liquid is an exotic state in insulating magnets, where conventional magnetic ordering is suppressed down to the lowest temperature by quantum fluctuations. Among the salient features is the fractionalization of quantum spins into emergent quasi-particles, such as spinons. Despite tremendous efforts for several decades, it is hard to identify the clear evidence of spin fractionalization in real materials. Most of such efforts have been done for asymptotic behaviors toward zero temperature, but they remain elusive due to extrinsic contributions inevitable at low temperatures. We here discuss more versatile signatures of the spin fractionalization in a wider temperature range, by taking the honeycomb Kitaev model. The Kitaev model provides an exact ground state being a quantum spin liquid, in which spins are fractionalized into itinerant Majorana fermions and localized Z2 fluxes. The model has attracted much attention since it is experimentally relevant to magnetic insulators with strong spin-orbit coupling, such as A2IrO3 and α-RuCl3. Beyond the exact ground state, we have investigated the static and dynamical properties of the Kitaev model at finite temperature, by developing new numerical techniques based on a Majorana fermion representation. We have unveiled the fingerprints of spin fractionalization in the temperature and energy dependences of various physical observables, such as the specific heat, magnetic susceptibility, NMR relaxation rate, dynamical spin structure factor, Raman scattering, and thermal transport. We will discuss the results in comparison with recent experimental data for the candidate materials. For references, visit http://www.motome-lab.t.u-tokyo.ac.jp/publication-e.html.
*This work is supported by Grant-in-Aid for Scientific Research under Grants No. JP15K13533, No. JP16H00987, No. JP16K17747, and No. JP16H02206. Parts of the numerical calculations were performed in the supercomputing systems in ISSP, the University of Tokyo.
The American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics.
1 Physics Ellipse, College Park, MD 20740-3844
Editorial Office 1 Research Road, Ridge, NY 11961-2701 (631) 591-4000
Office of Public Affairs 529 14th St NW, Suite 1050, Washington, D.C. 20045-2001 (202) 662-8700