Revealing the Empty-State Electronic Structure of Single-Unit-Cell FeSe/SrTiO3
Dennis Huang1, Can-Li Song1, Tatiana A Webb1,2
1Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Abstract:
We use scanning tunneling spectroscopy to investigate the filled and empty electronic states of superconducting single-unit-cell FeSe deposited on SrTiO3(001). We map the momentum-space band structure by combining quasiparticle interference imaging with decay length spectroscopy. In addition to quantifying the filled-state bands, we discover a Γ-centered electron pocket 75 meV above the Fermi energy. Our density functional theory calculations show the orbital nature of empty states at Γ and explain how the Se height is a key tuning parameter of their energies, with broad implications for electronic properties.
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