Detail: |
Abstract: Electronic transport of charge and spin can be controlled by external electric and magnetic fields. One of the most remarkable transport phenomena at mesoscale and nanoscale is the universal conductance fluctuation. Due to the quantum interference, the amplitude of such fluctuation stays constant independent of the average conductance and sample details. Based on a variety of nanomaterials, we will show results from perspectives of electrons intrinsic charge and spin properties. Then we discuss multiferroic materials which possess both ferroelectric and magnetic orderings, such that electric field can control magnetic properties and vice versa, magnetic field can control electric properties. Particularly we introduce the formation and characteristic of vortex/domain nanostructures in some perovskite oxides. Computational and theoretical methods employed in these studies will be introduced.
Reference: [1]“Universal Spin-Hall Conductance Fluctuations in Two Dimensions", Wei Ren, Zhenhua Qiao, Jian Wang, Qingfeng Sun, and Hong Guo, Phys. Rev. Lett. 97, 066603(2006). [2]“Prediction of the magnetotoroidic effect from atomistic simulations”, Wei Ren and L. Bellaiche, Phys. Rev.Lett., 107, 127202 (2011). [3]“Enhanced electric conductivity at ferroelectric vortex cores in BiFeO3”, N. Balke, B. Winchester, W. Ren, Y.H. Chu, A.N. Morozovska, E. Eliseev, M. Huijben, R.K. Vasudevan, V. Nagarajan, P. Maksymovych, J. Britson, S. Jesse, I. Kornev, R. Ramesh, L. Bellaiche, L.Q. Chen, and S. V. Kalinin, Nature Physics, 8, 81 (2012). [4]“Ferroelectric domains in multiferroic BiFeO3 films under epitaxial strains”, Wei Ren, Yurong Yang, Oswaldo Diéguez, Jorge Íñiguez, Narayani Choudhury, and L. Bellaiche, Phys. Rev. Lett., 110, 187601 (2013). [5]“Quantum Anomalous Hall Effect in Graphene Proximity-Coupled to an Antiferromagnetic Insulator”, Zhenhua Qiao, Wei Ren, Hua Chen, L. Bellaiche, Zhenyu Zhang, A.H. MacDonald, and Qian Niu, Phys. Rev. Lett., 112, 116404 (2014). |