Properties of the Dice-Lattice and its Ribbons
ORAL
Abstract
Previous theoretical studies established the existence of nearly flat bands with non-zero Chern numbers in the dice lattice using non-interacting electrons in the presence of spin-orbit coupling and magnetic field [1]. To pave the way towards the introduction of Hubbard
correlation effects via numerical methods here we explore if the main properties of the dice lattice survive in ribbons where one direction is made much shorter than the other [2]. Surprisingly, we find a rich eigenvalue spectrum that continues to display flat bands even for
the smallest ribbon such as the Nx2. Real-space charge currents moving along the edges clearly develop. We observed the presence of non-zero Hall-conductance (σHxy) and associated Quantum Anomalous Hall effect for all the ribbons investigated [3]. Time allowing, preliminary results for the effects of interaction (U) at half-filling on these ribbons will also be discussed using DMRG. In particular, for the Nx2 system when no magnetic field is present the ground state is ferri-magnetic increasing U. The evolution of the edge currents with increasing U will be presented.
[1] Wang et. al., PRB. 84, 241103 (2011)
[2] R. Soni, N. Kaushal, S. Okamoto, G. Alvarez, and E. Dagotto, submitted for publication.
[3] C. Chang et. al., Science 340, 6129 (2013)
correlation effects via numerical methods here we explore if the main properties of the dice lattice survive in ribbons where one direction is made much shorter than the other [2]. Surprisingly, we find a rich eigenvalue spectrum that continues to display flat bands even for
the smallest ribbon such as the Nx2. Real-space charge currents moving along the edges clearly develop. We observed the presence of non-zero Hall-conductance (σHxy) and associated Quantum Anomalous Hall effect for all the ribbons investigated [3]. Time allowing, preliminary results for the effects of interaction (U) at half-filling on these ribbons will also be discussed using DMRG. In particular, for the Nx2 system when no magnetic field is present the ground state is ferri-magnetic increasing U. The evolution of the edge currents with increasing U will be presented.
[1] Wang et. al., PRB. 84, 241103 (2011)
[2] R. Soni, N. Kaushal, S. Okamoto, G. Alvarez, and E. Dagotto, submitted for publication.
[3] C. Chang et. al., Science 340, 6129 (2013)
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Presenters
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Rahul Soni
University of Tennessee, Knoxville
Authors
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Rahul Soni
University of Tennessee, Knoxville
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Nitin Kaushal
University of Tennessee, Knoxville
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Elbio Dagotto
Department of Physics and Astronomy, University of Tennessee and ORNL, Physics Department, University of Tennessee, University of Tennessee, Department of Physics and Astronomy, University of Tennessee at Knoxville, University of Tennessee, Knoxville, and Oak Ridge National Laboratory, University of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee
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Satoshi Okamoto
Oak Ridge National Lab, Materials Science and Technology Division, Oak Ridge National Laboratory, University of Tennessee, Knoxville, Oak Ridge National Laboratory