Negative Oxygen Isotope Effect on the Static Spin Stripe Order in La_(2-x)Ba_xCuO_4 (x = 1/8)

TL;DR

This study reveals a significant negative oxygen isotope effect on static spin stripe order in La_(2-x)Ba_xCuO_4, highlighting the role of electron-lattice interactions in the competition between stripe order and superconductivity.

Contribution

It demonstrates the negative oxygen isotope effect on spin stripe order and magnetic volume fraction, providing new insights into electron-lattice interactions in cuprate superconductors.

Findings

Negative isotope effect on spin stripe ordering temperature and magnetic volume fraction.

Sign reversal of isotope effect exponents compared to superconducting transition.

Evidence of electron-lattice interaction's role in stripe formation and superconductivity competition.

Abstract

Large negative oxygen-isotope (16O/18O) effects (OIE's) on the static spin-stripe ordering temperature T_so and the magnetic volume fraction V_m were observed in La_(2-x)Ba_xCuO_4 (x = 1/8) by means of muon spin rotation experiments. The corresponding OIE exponents were found to be alpha_(T_so) = -0.57(6) and alpha_(V_m) = -0.71(9), which are sign reversed to alpha_(T_c) = 0.46(6) measured for the superconducting transition temperature T_c. This indicates that the electron-lattice interaction is involved in the stripe formation and plays an important role in the competition between bulk superconductivity and static stripe order in the cuprates.