Abstract
A magnetic order can be completely suppressed at zero temperature (), by doping carriers or applying pressure, at a quantum critical point, around which physical properties change drastically. However, the situation is unclear for an electronic nematic order that breaks rotation symmetry. Here, we report nuclear magnetic resonance studies on where magnetic and nematic transitions are well separated. The nuclear magnetic resonance spectrum is sensitive to inhomogeneous magnetic fields in the vortex state, which is related to London penetration depth that measures the electron mass . We discovered two peaks in the doping dependence of , one at where the spin-lattice relaxation rate shows quantum critical behavior, and another at around which the nematic transition temperature extrapolates to zero and the electrical resistivity shows a -linear variation. Our results indicate that a nematic quantum critical point lies beneath the superconducting dome at where is enhanced. The impact of the nematic fluctuations on superconductivity is discussed.
- Received 13 March 2018
- Revised 5 June 2018
DOI:https://doi.org/10.1103/PhysRevLett.121.167004
© 2018 American Physical Society