[Paper Review] Elucidation of the origins of HTSC transport behaviour and quantum oscillations

J. A. Wilson|ArXiv.org|Nov 19, 2008

Physics of Superconductivity and Magnetism7 references3 citations

TL;DR

This paper reinterprets high-temperature superconductor (HTSC) transport and quantum oscillation data through a framework of local pairs and boson-fermion resonance in inhomogeneous, mixed-valent systems near the Mott-Anderson transition. It attributes observed oscillations not to a Fermi surface in a conventional Fermi liquid, but to fluxon lattice ordering within a 2D diagonal charge stripe array, with the flux quantum effectively doubling to h/e under high magnetic fields.

ABSTRACT

A detailed exposition is made of recent transport and 'quantum oscillation' results from HTSC systems covering the full range from overdoped to underdoped material. This now very extensive and high quality data set is interpreted here within the framework developed by the author of local pairs and boson-fermion resonance, arising in the context of negative-U behaviour in an inhomogeneous electronic environment. The strong inhomogeneity comes with the mixed-valent condition of these materials, which when underdoped lie in close proximity to the Mott-Anderson transition. The observed intense scattering is presented as resulting from pair formation and electron-boson collisions in the resonant crossover circumstance. The high level of scattering brings the systems to incoherence in the pseudogapped state, p < pc (= 0.183). In a high magnetic field the striped partition of the inhomogeneous charge distribution is much strengthened and regularized. Magnetization and resistance oscillations, of period dictated by the favoured positioning of the square fluxon array within the real space environment of the diagonal 2D charge striping array, are demonstrated to be responsible for the recently reported behaviour hitherto widely attributed to the quantum oscillation response of a much more standard Fermi liquid condition. A detailed analysis embracing all the experimental data serves to indicate that in the given conditions of very high field, low temperature, 2D-striped, underdoped, d-wave superconducting, HTSC material the flux quantum becomes doubled to h/e.

Motivation & Objective

• To resolve the long-standing puzzle of quantum oscillations in underdoped cuprates, which contradict expectations from conventional Fermi liquid theory.
• To explain the origin of transport incoherence and pseudogap behavior in HTSC materials across the overdoped to underdoped regime.
• To demonstrate that observed oscillations arise from fluxon lattice dynamics in a 2D striped charge environment, not from a Fermi surface.
• To unify transport, quantum oscillation, and incoherence phenomena within a single framework of local pairing and resonant scattering.

Proposed method

• Analyzes extensive experimental transport and quantum oscillation data from overdoped to underdoped HTSC materials.
• Applies a theoretical framework based on local pairs and boson-fermion resonance in a negative-U, inhomogeneous electronic environment.
• Models the system as near the Mott-Anderson transition, with strong electron-boson scattering due to mixed-valence and charge inhomogeneity.
• Introduces a resonant crossover mechanism where pair formation and scattering lead to incoherence in the pseudogapped state (p < pc = 0.183).
• Predicts that high magnetic fields regularize the inhomogeneous charge distribution into diagonal 2D stripes, stabilizing a square fluxon lattice.
• Derives that the flux quantum becomes effectively h/e due to the spatial periodicity of the stripe array, leading to oscillations with a period dictated by this real-space structure.

Experimental results

Research questions

• RQ1 What causes the observed quantum oscillations in underdoped HTSC materials if not a Fermi surface?
• RQ2 Why does the system exhibit transport incoherence and pseudogap behavior in the underdoped regime?
• RQ3 How does the presence of charge stripes and magnetic fields influence the fluxon lattice and quantum oscillation period?
• RQ4 What is the origin of the apparent doubling of the flux quantum to h/e in high-field experiments?
• RQ5 Can the observed transport and oscillation behavior be consistently explained by a local pairing and resonant scattering mechanism rather than a Fermi liquid model?

Key findings

• The observed quantum oscillations in high magnetic fields arise from the periodic arrangement of fluxons within a diagonal 2D charge stripe array, not from a Fermi surface.
• The flux quantum is effectively doubled to h/e due to the spatial periodicity of the stripe structure, which modulates the fluxon lattice.
• Transport incoherence in the pseudogapped state (p < 0.183) results from intense scattering due to local pair formation and electron-boson resonance.
• High magnetic fields strengthen and regularize the inhomogeneous charge distribution, stabilizing a well-ordered fluxon lattice.
• The entire dataset, including resistance and magnetization oscillations, is consistently explained by the proposed inhomogeneous, resonant pairing model.
• The framework unifies pseudogap behavior, incoherence, and quantum oscillations within a single mechanism rooted in local pairing and resonant scattering.