Effect of Impurity on the Doping-Induced in-Gap States in a Mott Insulator
Cheng-Ping He1, Shun-Li Yu1,2, Tao Xiang3,4,5*, and Jian-Xin Li1,2*
1National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China 2Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China 3Institute of Physics, National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China 4Department of Physics, University of Chinese Academy of Sciences, Beijing 100190, China 5Beijing Academy of Quantum Information Sciences, Beijing 100193, China
Abstract：Motivated by the recent measurements of the spatial distribution of single particle excitation states in a hole-doped Mott insulator, we study the effects of impurity on the in-gap states, induced by the doped holes, in the Hubbard model on the square lattice by the cluster perturbation theory. We find that a repulsive impurity potential can move the in-gap state from the lower Hubbard band towards the upper Hubbard band, providing a good account for the experimental observation. The distribution of the spectral function in the momentum space can be used to discriminate the in-gap state induced by doped holes and that by the impurity. The spatial characters of the in-gap states in the presence of two impurities are also discussed and compared to the experiment.
. [J]. 中国物理快报, 2022, 39(5): 57401-057401.
Cheng-Ping He, Shun-Li Yu, Tao Xiang, and Jian-Xin Li. Effect of Impurity on the Doping-Induced in-Gap States in a Mott Insulator. Chin. Phys. Lett., 2022, 39(5): 57401-057401.
2022, Vol. 39 
