{"id":466,"date":"2017-09-27T20:22:50","date_gmt":"2017-09-27T20:22:50","guid":{"rendered":"http:\/\/girsh.rutgers.edu\/?p=466"},"modified":"2017-09-27T23:03:19","modified_gmt":"2017-09-27T23:03:19","slug":"chiral-spin-mode-on-the-surface-of-a-topological-insulator","status":"publish","type":"post","link":"https:\/\/girsh.rutgers.edu\/index.php\/2017\/09\/27\/chiral-spin-mode-on-the-surface-of-a-topological-insulator\/","title":{"rendered":"New paper published – Chiral Spin Mode on the Surface of a Topological Insulator"},"content":{"rendered":"


\nAuthors:<\/strong> H.-H. Kung, S. Maiti, X. Wang, S.-W. Cheong, D.L. Maslov, G. Blumberg<\/p>\n

Abstract:<\/strong><\/p>\n

Using polarization-resolved resonant Raman spectroscopy, we explore collective spin excitations of the chiral surface states in a three dimensional topological insulator, Bi2<\/sub>Se3<\/sub>. We observe a sharp peak at 150 meV in the pseudovector A2<\/sub> symmetry channel of the Raman spectra. By comparing the data with calculations, we identify this peak as the transverse collective spin mode of surface Dirac fermions. This mode, unlike a Dirac plasmon or a surface plasmon in the charge sector of excitations, is analogous to a spin wave in a partially polarized Fermi liquid, with spin-orbit coupling playing the role of an effective magnetic field.<\/div>\n
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