Photoemission study of the electronic structure and charge density waves of Na2Ti2Sb2O.
The electronic structure of Na2Ti2Sb2O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na2Ti2Sb2O in the non-magnetic state, which indicates that there is no magnetic order in Na2Ti2Sb2O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na2Ti2Sb2O. Photon energy dependent ARPES results suggest that the electronic structure of Na2Ti2Sb2O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV at 7 K, indicating that Na2Ti2Sb2O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime.
1] Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907, China [2] Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
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Tan
1] Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Jiang
Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
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Ye
1] Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Niu
Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
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Song
1] Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA [2] Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
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Zhang
Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
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Dai
1] Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Xie
Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907, China.
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Lai
1] Physics Department, Applied Surface Physics State Key Laboratory, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Feng