Cooling a polaronic liquid: Phase mixture and pseudogap-like spectra in superconducting $B{a}_{1-x}{K}_{x}Bi{O}_3$

Abstract

Many complex electronic systems exhibit so-called pseudogaps, which are poorly-understood suppression of low-energy spectral intensity in the absence of an obvious gap-inducing symmetry. Here we investigate the superconductor $B{a}_{1-x}{K}_{x}Bi{O}_3$ near optimal doping, where unconventional transport behavior and evidence of pseudogap(s) have been observed above the superconducting transition temperature $T_c$, and near an insulating phase with long-range lattice distortions. Angle-resolved photoemission spectroscopy (ARPES) reveals a dispersive band with vanishing quasiparticle weight and "tails" of deep-energy intensity that strongly decay approaching the Fermi level. Upon cooling below a transition temperature $T_p>T_c$, which correlates with a change in the slope of the resistivity vs. temperature, a partial transfer of spectral weight near $E_F$ into the deep-binding energy tails is found to result from metal-insulator phase separation. Combined with simulations and Raman scattering, our results signal that insulating islands of ordered bipolarons precipitate out of a disordered polaronic liquid and provide evidence that this process is regulated by a crossover in the electronic mean free path.

References in corpus (17)

• Site-selective Mott transition in rare earth nickelates
• Tunable polaronic conduction in anatase TiO2
• Ground state oxygen holes and the metal-insulator transition in the negative charge transfer rare-earth nickelates
• Charge disproportionation without charge transfer in the rare-earth nickelates as a possible mechanism for the metal-insulator transition
• Tailoring the nature and strength of electron-phonon interactions in the SrTiO${}_3$(001) two-dimensional electron liquid
• Laser ARPES, the sudden approximation, and quasiparticle-like peaks in Bi2Sr2CaCu2O8+delta
• Polaronic hole-trapping in doped $\mathrm{BaBi}{\mathrm{O}}_3$
• Hybridization effects and bond-disproportionation in the bismuth perovskites
• Quasiparticle-like peaks, kinks, and electron-phonon coupling at the ($\pi$,0) regions in the CMR oxide La${}_{2-2x}$Sr${}_{1+2x}$Mn${}_2$O${}_7$
• Momentum-Resolved Electronic Structure of the High-$T_c$ Superconductor Parent Compound BaBiO${}_3$
• Oxygen holes and hybridization in the bismuthates
• Stripe-like nanoscale structural phase separation and optimal inhomogeneity in superconducting BaPb${}_{1-x}$Bi${}_x$O${}_3$
• Bilayer manganites: polarons in the midst of a metallic breakdown
• Tuning the metal-insulator transition in NdNiO3 heterostructures via Fermi surface instability and spin-fluctuations
• Electron-phonon coupling induced pseudogap and the superconducting transition in Ba0.67K0.33BiO3
• Anomalous relaxation kinetics and charge density wave correlations in underdoped BaPb1-xBixO3
• Unusual temperature dependence of the spectral weight near the Fermi level of NdNiO3 thin films

Cited by in corpus (4)

• Quantum Monte Carlo study of lattice polarons in the two-dimensional multi-orbital Su-Schrieffer-Heeger model
• Bipolaron liquids at strong Peierls electron-phonon couplings
• A hybrid Monte Carlo study of bond-stretching electron-phonon interactions and charge order in BaBiO${}_3$
• Polaron and bipolaron tendencies in a semiclassical model for hole-doped bismuthates