节点文献
Revealing the A1g-type strain effect on superconductivity and nematicity in FeSe thin flake
【摘要】 The driving mechanism of nematicity and its twist with superconductivity in iron-based superconductors are still under debate.Recently,a dominant B1 g-type strain effect on superconductivity is observed in underdoped iron-pnictides superconductors Ba(Fe1-xCox)2 As2,suggesting a strong interplay between nematicity and superconductivity.Since the long-range spin order is absent in FeSe superconductor,whether a similar strain effect could be also observed or not is an interesting question.Here,by utilizing a flexible film as substrate,we successfully achieve a wide-range-strain tuning of FeSe thin flake,in which both the tensile and compressive strain could reach up to ~0.7%,and systematically study the strain effect on both superconducting and nematic transition(Tc and Ts) in the FeSe thin flake.Our results reveal a predominant A1 g-type strain effect on Tc.Meanwhile,Ts exhibits a monotonic anti-correlation with Tc and the maximum Tc reaches to 12 K when Ts is strongly suppressed under the maximum compressive strain.Finally,in comparison with the results in the underdoped Ba(Fe1-xCox)2 As2,the absence of B1 g-type strain effect in FeSe further supports the role of stripe-type spin fluctuations on superconductivity.In addition,our work also supports that the orbital degree of freedom plays a key role to drive the nematic transition in FeSe.
【Abstract】 The driving mechanism of nematicity and its twist with superconductivity in iron-based superconductors are still under debate.Recently,a dominant B1 g-type strain effect on superconductivity is observed in underdoped iron-pnictides superconductors Ba(Fe1-xCox)2 As2,suggesting a strong interplay between nematicity and superconductivity.Since the long-range spin order is absent in FeSe superconductor,whether a similar strain effect could be also observed or not is an interesting question.Here,by utilizing a flexible film as substrate,we successfully achieve a wide-range-strain tuning of FeSe thin flake,in which both the tensile and compressive strain could reach up to ~0.7%,and systematically study the strain effect on both superconducting and nematic transition(Tc and Ts) in the FeSe thin flake.Our results reveal a predominant A1 g-type strain effect on Tc.Meanwhile,Ts exhibits a monotonic anti-correlation with Tc and the maximum Tc reaches to 12 K when Ts is strongly suppressed under the maximum compressive strain.Finally,in comparison with the results in the underdoped Ba(Fe1-xCox)2 As2,the absence of B1 g-type strain effect in FeSe further supports the role of stripe-type spin fluctuations on superconductivity.In addition,our work also supports that the orbital degree of freedom plays a key role to drive the nematic transition in FeSe.
【Key words】 iron-based superconductors; superconductivity; electronic nematicity; strain effect;
- 【文献出处】 Chinese Physics B ,中国物理B , 编辑部邮箱 ,2021年09期
- 【分类号】O511.3
- 【下载频次】9