CM/BIO/ECE Seminar Series Presents: Dr. Arnab Banerjee

Wednesday, February 21, 2018 4:00pm

Physics Library, Room 223A, Physics Building

Departments: 

The MU Physics & Astronomy Department's Condensed Matter - Biological Physics - Electrical & Computer Engineering seminar series presents, "Topological Excitations in a Honeycomb Kitaev Spin-Liquid Candidate," Wednesday, Feb. 21, 4:00 p.m. in the Physics Building library. Refreshments will be served beginning at 3:30 p.m.

Dr. Arnab Banerjee, Oak Ridge National Laboratory

Dr. Arnab Banerjee, Oak Ridge National Laboratory, writes, "The Kitaev model on a honeycomb lattice predicts a special quantum spin liquid (QSL) ground state with excitations resembling Majorana Fermions and gauge flux excitations. These emergent features are exciting prospects, to both basic physics and applications towards a lossless technology for quantum qubits.  In this talk, I will describe our recent range of experiments on the magnetic Mott insulator alpha-RuCl3, which has honeycomb layers held together with weak van-der-Waals interactions. A strong spin-orbit coupling and an octahedral crystal field makes the Kitaev interactions the leading order term in the Hamiltonian. Prominently, despite a long-range ordered ground state, our inelastic neutron scattering measurements reveal a continuum of fractionalized excitations resembling predictions from Majorana Fermions, confirming that the material is proximate to a QSL. In an 8T magnetic field the long-range order vanishes, revealing a true QSL with gapped excitations, raising hopes of a state where non-Abelian excitations can reside. This opens prospects for future experiments which can directly probe the signatures of quantum coherence in this material."