Scanning tunneling microscopy/spectroscopy studies of monolayer FeTe on SrTiO3(001) - √13⨯√13
ORAL
Abstract
Bulk FeTe shows a bicollinear antiferromagnetic order under 65 K [1], but recent angle-resolved photoemission and scanning tunneling spectroscopy research also revealed a Kondo-like behavior in FeTe [2], showing that the ground state of FeTe is complicated. Our previous research showed that SrTiO3(001)-√13⨯√13 substrate leads to a C2 symmetry on monolayer (ML) FeSe, a cousin of FeTe; furthermore, we found that the electron doping from the SrTiO3 surface locally modulates the superconducting gap size of ML FeSe [3]. These prompt several questions: 1. Can the SrTiO3-√13⨯√13 substrate lower the rotational symmetry on the isostructural ML FeTe? 2. Can the Kondo behavior be confirmed on the ML FeTe? 3. Can the SrTiO3 substrate locally modulate the ground state of ML FeTe?
To clarify the above points, we performed low-temperature scanning tunneling microscopy/spectroscopy (STM/STS, T: 5 K ~ 77 K) experiments on the ML FeTe/SrTiO3-√13⨯√13.
Results [4]:
1. The STM data indicates a substrate-induced C2 rotational symmetry on ML FeTe, similar to ML FeSe on SrTiO3-√13⨯√13.
2. The STS spectra obtained on ML FeTe show Fano-line shape near the Fermi level, illustrating a Kondo scenario that localized Fe spins are screened by the conduction electrons.
3. Two types of Fano-line spectra were confirmed, and their spatial dependence follows the √13⨯√13 periodicities, indicating that the SrTiO3 substrate can modulate the interaction between the localized spin and conduction electrons mentioned above.
Details will be given in the presentation.
To clarify the above points, we performed low-temperature scanning tunneling microscopy/spectroscopy (STM/STS, T: 5 K ~ 77 K) experiments on the ML FeTe/SrTiO3-√13⨯√13.
Results [4]:
1. The STM data indicates a substrate-induced C2 rotational symmetry on ML FeTe, similar to ML FeSe on SrTiO3-√13⨯√13.
2. The STS spectra obtained on ML FeTe show Fano-line shape near the Fermi level, illustrating a Kondo scenario that localized Fe spins are screened by the conduction electrons.
3. Two types of Fano-line spectra were confirmed, and their spatial dependence follows the √13⨯√13 periodicities, indicating that the SrTiO3 substrate can modulate the interaction between the localized spin and conduction electrons mentioned above.
Details will be given in the presentation.
* This work has been supported by JSPS KAKENHI. Grant Numbers: JP22H04502, JP22K18966, 20H05183.
–
Publication: [1] Shiliang Li et al., Phys. Rev. B 79, 054503 (2009).
[2] Younsik Kim et al., Nat. Commun. 14, 4145 (2023).
[3] Wen Si et al., Phys. Rev. B 105, 104502 (2022).
[4] Wen Si et al., to be submitted.
Presenters
-
Wen Si
the University of Tokyo; Tokyo Institute of Technology
Authors
-
Wen Si
the University of Tokyo; Tokyo Institute of Technology
-
Bin Yu
Tokyo Institute of Technology
-
Satoru Ichinokura
Tokyo Institute of Technology
-
Toru Hirahara
Tokyo Institute of Technology