Unconventional short-range structural fluctuations in cuprate high-$T_c$ superconductors

Abstract

The interplay between structural and electronic degrees of freedom in complex materials is the subject of extensive debate in physics and materials science. Particularly interesting questions pertain to the nature and extent of pre-transitional short-range order in diverse systems ranging from shape-memory alloys to unconventional superconductors, and how this microstructure affects macroscopic properties. Here we use neutron and X-ray diffuse scattering to uncover universal structural fluctuations in La${}_{2-x}$Sr${}_x$CuO${}_4$ and Tl${}_2$Ba${}_2$CuO${}_{6+\delta }$, two cuprate superconductors with distinct point disorder effects and optimal superconducting transition temperatures. The fluctuations are present in wide doping and temperature ranges, including compositions that maintain high average structural symmetry, and they exhibit unusual, yet simple scaling behavior. The scaling regime is robust and universal, similar to the well-known critical fluctuations close to second-order phase transitions, but with a distinctly different physical origin. We relate this behavior to pre-transitional phenomena in a broad class of systems with structural and magnetic transitions, and propose an explanation based on rare structural fluctuations caused by intrinsic nanoscale inhomogeneity. We also uncover parallels with superconducting fluctuations, which indicates that the underlying inhomogeneity plays an important role in cuprate physics.

24 pages, 4 figures

References in corpus (9)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• Scale-free structural organization of oxygen interstitials in La2CuO4+y
• Electronic Origin of the Inhomogeneous Pairing Interaction in the High-Tc Superconductor Bi2Sr2CaCu2O8+d
• Giant thermal Hall conductivity from neutral excitations in the pseudogap phase of cuprates
• Incommensurate lattice distortion in the high temperature tetragonal phase of La${}_{2-x}$(Sr,Ba)${}_x$CuO${}_4$
• ${}^{139}$La NMR investigation in underdoped La${}_{1.93}$Sr${}_{0.07}$CuO${}_4$
• Electron-phonon coupling and superconductivity in the doped topological-crystalline insulator (Pb${}_{0.5}$Sn${}_{0.5}$)${}_{1-x}$In${}_x$Te
• Phenomenological model for the third-harmonic magnetic response of superconductors: application to Sr${}_2$RuO${}_4$

Cited by in corpus (7)

• Dynamic Nanodomains Dictate Macroscopic Properties in Lead Halide Perovskites
• High-T${}_c$ cuprates: a story of two electron subsystems
• Diffuse Scattering from Correlated Electron Systems
• Probing Short-Range Correlations in the van der Waals Magnet CrSBr by Small-Angle Neutron Scattering
• Nanoscale structural correlations in a model cuprate superconductor
• Doping Dependence of Spin-Momentum Locking in Bismuth-Based High-Temperature Cuprate Superconductors
• Phonon Induced Energy Relaxation in Quantum Critical Metals