High magnetic field ultrasound study of spin freezing in La1.88Sr0.12CuO4

Abstract

High-Tc cuprate superconductors host spin, charge and lattice instabilities. In particular, in the antiferromagnetic glass phase, over a large doping range, lanthanum based cuprates display a glass-like spin freezing with antiferromagnetic correlations. Previously, sound velocity anomalies in La2−xSrxCuO4 (LSCO) for hole doping p ≥ 0.145 were reported and interpreted as arising from a coupling of the lattice to the magnetic glass [Frachet, Vinograd et al., Nat. Phys. 16, 1064-1068]. Here we report both sound velocity and attenuation in LSCO p = 0.12, i.e. at a doping level for which the spin freezing temperature is the highest. Using high magnetic fields and comparing with nuclear magnetic resonance (NMR) measurements, we confirm that the anomalies in the low temperature ultrasound properties of LSCO are produced by a coupling between the lattice and the spin glass. Moreover, we show that both sound velocity and attenuation can be simultaneously accounted for by a simple phenomenological model originally developed for canonical spin glasses. Our results point towards a strong competition between superconductivity and spin freezing, tuned by the magnetic field. A comparison of different acoustic modes suggests that the slow spin fluctuations have a nematic character.

Using strain to uncover the interplay between two- and three-dimensional charge density waves in high-temperature superconducting YBa2Cu3Oy

“…Next, we briefly discuss our structural results in the context of nematicity, largely associated with the growth of spin and charge-density-wave correlations upon cooling [46][47][48][49][50] in the cuprates. In the unstrained orthorhombic unit cell the buckling angles along a and b axes differ only slightly.…”

Evidence for a square-square vortex lattice transition in a high-$T_\textrm{c}$ cuprate superconductor

“…Arrows mark the decrease associated with vortex lattice depinning at B dp . Note that p = 0.10 and 0.11 data are at 4.2 K, all the others are at 1.5 K. The VL contribution appears on top of a background sound velocity, which is associated with the field-dependent electronic properties of LSCO such as superconductivity and magnetism [29,30]. This nonvortex background is significant for p ≤ 0.145 but diminishes smoothly with doping.…”

Second order Zeeman interaction and ferroquadrupolar order in TmVO$_4$

“…These two effects may conspire to give rise to the broad maximum when T ∼ ∆/k B , which itself is fielddependent. Comparison of NMR relaxation rates with other low-frequency dynamic probes, such as ultrasound attenuation, can be fruitful [38], however there is no report of ultrasound experiments with fields applied in the plane to allow direct comparison.…”