The emergence of global phase coherence from local pairing in underdoped cuprates

Abstract

In conventional metal superconductors such as aluminum, the large number of weakly bounded Cooper pairs become phase coherent as soon as they start to form. The cuprate high critical temperature ($T_c$) superconductors, in contrast, belong to a distinctively different category. To account for the high $T_c$, the attractive pairing interaction is expected to be strong and the coherence length is short. Being doped Mott insulators, the cuprates are known to have low superfluid density, thus are susceptible to phase fluctuations. It has been proposed that pairing and phase coherence may occur separately in cuprates, and $T_c$ corresponds to the phase coherence temperature controlled by the superfluid density. To elucidate the microscopic processes of pairing and phase ordering in cuprates, here we use scanning tunneling microscopy to image the evolution of electronic states in underdoped $\mathrm{B}{\mathrm{i}}_2\mathrm{L}{\mathrm{a}}_{\mathrm{x}}\mathrm{S}{\mathrm{r}}_{2-\mathrm{x}}\mathrm{Cu}{\mathrm{O}}_{6+\delta }$. Even in the insulating sample, we observe a smooth crossover from the Mott insulator to superconductor-type spectra on small islands with chequerboard order and emerging quasiparticle interference patterns following the octet model. Each chequerboard plaquette contains approximately two holes, and exhibits a stripy internal structure that has strong influence on the superconducting features. Across the insulator to superconductor boundary, the local spectra remain qualitatively the same while the quasiparticle interferences become long-ranged. These results suggest that the chequerboard plaquette with internal stripes plays a crucial role on local pairing in cuprates, and the global phase coherence is established once its spatial occupation exceeds a threshold.

References in corpus (16)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+d
• Charge density wave origin of cuprate checkerboard visualized by scanning tunneling microscopy
• How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+d
• Electronic Origin of the Inhomogeneous Pairing Interaction in the High-Tc Superconductor Bi2Sr2CaCu2O8+d
• Visualizing the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator
• Visualizing the periodic modulation of Cooper pairing in a severely underdoped cuprate
• Stripe order enhanced superconductivity in the Hubbard model
• Gapless superconductivity and the Fermi arc in the cuprates
• Direct observation of charge order in underdoped and optimally doped Bi${}_2$(Sr,La)${}_2$CuO${}_{6+\delta }$ by resonant inelastic x-ray scattering
• Onset of a boson mode at superconducting critical point of underdoped YBa2Cu3Oy
• Bogoliubov angle and visualization of particle-hole mixture in superconductors
• An inhomogeneous Josephson phase in thin-film and High-Tc superconductors
• The n_s - T_c correlations in granular superconductors
• Quasiparticle Interference in STM As a Function of Temperature: Signatures of Coherence
• Superconductivity from charge order in cuprates

Cited by in corpus (11)

• Signatures of two gaps in the spin susceptibility of a cuprate superconductor
• Stripe Symmetry of Short-range Charge Density Waves in Cuprate Superconductors
• Unprecedentedly large gap in HgBa${}_2$Ca${}_2$Cu${}_3$O${}_{8+\delta }$ with the highest $T_c$ at ambient pressure
• Quantum colored strings in the hole-doped $t$-$J_z$ model
• Unveiling Stripe-shaped Charge Density Modulations in Doped Mott Insulators
• Persistence of vortexlike phase fluctuations in underdoped to heavily overdoped Bi-2201 cuprates
• Vortex-driven periodic and aperiodic magnetoresistance oscillations in cuprates
• Possible Spatial Correlation of Superconducting and Pseudogap Dynamics in a Bi-based Cuprate
• Spinon Singlet Pairing: Origin of $d$-Wave Sign Structure in a Partially-Filled Stripe
• "Half-Bogoliubons" as the intermediate states for the phase coherence in underdoped cuprates
• Percolative Pathway to Stripe Order in KTaO3-Based Superconductivity