光在介电体超晶格中传播的理论分析.ppt

Quantum Spin Hall Effect  Journal Club JIAN LIU Artificial Quantum Matter Laboratory Quantum, Spin, Hall Effect Hall Effect Quantum State of Electron in Magnetic Field Quantum Hall Effect Quantum Hall Effect Electron Motion is Uniform Electric Magnetic Field Impurity Edge States Spin Hall Effect Quantum Version of Spin Hall Effect Ingredients Ingredients Topological States The End * * Breakthrough of 2007 The discovery could open the door to new low-power spintronic computing devices that manipulate electrons by both charge and spin. Hall Effect Edwin Hall, 1879 Quantum Hall Effect (integer) Klaus von Klitzing, 1980 (1986 Nobel Prize) Spin Hall Effect M.I. Dyakonov and V.I, Perel, 1972 Y. Kato et al, 2005 J. Wunderich et al, 2006 Quantum Spin Hall Effect B V Broadening Landau Levels Impurities Edge states Motion in uniform electric magnetic field Move along equal potential lines. Energy is still quantized into Landau Levels. Landau Levels are shifted. Newton’s 2nd Law Quantum Mechanics V Summit Basin Move along equal potential lines. Energy is still quantized into Landau Levels. Landau Levels are shifted. Relativistic effect Energy (Spin Orbital Interaction) Quantum Spin Hall Effect B B Band gap Localization in bulk Edge states Insulator Strong Spin Orbital Interaction p s p1/2 p3/2 s p1/2 p3/2 s HgTe HgTe CdTe CdTe CdTe CdTe Valence Band Conduction Band Valence Band Conduction Band Experimental Result HgTe HgTe CdTe CdTe CdTe CdTe Experimental Result Valence Band Conduction Band Valence Band Conduction Band Quantum Hall Effect Quantum Spin Hall Effect Topological Protected Topological Invariants Topological Trivial States Thank you! * *