Probing Low Energy Excitations in 2D Short Range Ordered (Spin Liquid) Phases

Prof. Vesna Mitrovic,

Department of Physics,

Brown University, USA.

刘德胜 教授

2013-12-15 10:00

知新楼C702 量子报告厅

In this talk, notion of the quantum spin liquid will be introduced. Nature of possible spin liquid states that can arise in frustrated antiferromagnets on 2D lattices, and in particular on an anisotropic triangular lattice, will de discussed. We will describe how nuclear magnetic resonance (NMR) measurements can provide a powerful tool for probing the relevant low energy excitations, and thus the nature of the spin liquid states. Result obtained in a model system of spin-1/2 anisotropic triangular lattice antiferromagnet Cs2CuCl4 will be presented. These results indicate that the spin liquid state in this compound is characterized by low-energy excitations that are fractional (spinons) and obey fermionic statistics.

Prof. Vesna Mitrovic

Professor Mitrovic joined the Physics Department at Brown University in 2003. A graduate of Illinois Institute of Technology, she received her Ph.D. from Northwestern University in 2001. She has done postdoctoral work at Grenoble High Magnetic Field Laboratory (Grenoble, France).

Her research interests include study of the quantum phenomena arising in strongly correlated electron systems at low temperatures and high magnetic fields using NMR spectroscopy.

Quantum Magnetism: 2D spin-liquids - we are undertaking microscopic studies of the 2D frustrated spin-1/2 Heisenberg antiferromagnet, Cs2CuCl4. This material represents the first experimental realization of a 2D fractional quantum spin liquid.

Superconductivity: What is the role of magnetism in establishing unconventional superconductivity? We are investigating quantum critical phenomena and exotic magnetic field induced superconducting phases in heavy-fermion superconductors.