Nuclear magnetic resonance techniques for in-situ strain measurements using surface coils

Widespread efforts have been made to study the role of nematic order in the high temperature superconductivity of iron-based pnictides. This includes the increasing use of strain to explore the anisotropies in electronic states and the nematic susceptibility. Nuclear magnetic resonance (NMR) is the ideal probe to explore such properties because it is sensitive to spin and charge degrees of freedom while allowing the measurement of nematic properties in the superconducting state. It has been shown that strain can be fully transmitted to samples up to approximately 100 μm thick using piezoelectric stacks [J.H. Chu et al. Science 2012], but there are practical limitations in the application of such techniques in NMR. The nontrivial issue of probing such small samples can be overcome by the novel use of surface coils that enhance the signal to noise ratio [W. Liu et al. Rev. Sci. Instrum. 2017] and allow for in-situ sample rotations and controllable application of strain. In this talk, we demonstrate how to simultaneously implement such techniques in NMR experiments.