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Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
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Strong interplay between stripe spin fluctuations, nematicity and superconductivity in FeSe
Qisi Wang1, Yao Shen1, Bingying Pan1
1State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
Nature Materials
|December 8, 2015
Summary
Spin fluctuations drive both nematicity and superconductivity in iron-based superconductors like FeSe. Neutron scattering reveals these fluctuations are enhanced near the nematic transition, linking them to superconductivity.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- In iron-based superconductors, the interactions causing nematic order might also mediate Cooper pairing.
- Determining these interactions is challenging due to nematic order occurring near stripe magnetic ordering temperatures.
- FeSe exhibits a nematic phase transition at 90 K without antiferromagnetic ordering.
Purpose of the Study:
- To investigate the relationship between nematicity and spin fluctuations in the iron-based superconductor FeSe.
- To understand the role of spin fluctuations in mediating superconductivity in FeSe.
Main Methods:
- Neutron scattering experiments were performed on FeSe.
- Scanning tunnelling spectroscopy was used to reveal electron-boson coupling modes.
Main Results:
- Substantial stripe spin fluctuations coupled with nematicity were observed in FeSe, enhancing upon cooling through the transition temperature (Ts).
- A sharp spin resonance at approximately 4 meV developed in the superconducting state, consistent with electron-boson coupling.
- The magnetic spectral weight in FeSe was comparable to that in iron arsenides.
Conclusions:
- The findings support theoretical proposals that spin fluctuations drive both nematicity and superconductivity in iron-based superconductors.
- The study highlights the crucial role of spin dynamics in the emergence of superconductivity in FeSe.
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