Local and non-local electron-phonon couplings in K3Picene and the effect of metallic screening

Abstract

We analyze the properties of electron-phonon couplings in K3Picene by exploiting a molecular orbital representation derived in the maximally localized Wannier function formalism. This allows us to go beyond the analysis done in Phys. Rev. Lett. 107, 137006 (2011), and separate not only the intra- and intermolecular phonon contributions but also the local and non-local electronic states in the electron-phonon matrix elements. Despite the molecular nature of the crystal, we find that the purely molecular contributions (Holstein-like couplings where the local deformation potential is coupled to intramolecular phonons) account for only 20% of the total electron-phonon interaction lambda. In particular, the Holstein-like contributions to lambda in K3Picene are four times smaller than those computed for an isolated neutral molecule, as they are strongly screened by the metallic bands of the doped crystal. Our findings invalidate the use of molecular electron-phonon calculations to estimate the total electron-phonon coupling in metallic picene, and possibly in other doped metallic molecular crystals. The major contribution (80%) to lambda in K3Picene comes from non-local couplings due to phonon modulated hoppings. We show that the crystal geometry together with the molecular picene structure leads to a strong 1D spatial anisotropy of the non-local couplings. Finally, based on the parameters derived from our density functional theory calculations, we propose a lattice modelization of the electron-phonon couplings in K3Picene which gives 90% of ab-initio lambda.

13 pages, 8 figures, 3 tables

References in corpus (7)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Electronic transport through electron-doped Metal-Phthalocyanine Materials
• Electronic Correlation effects in superconducting picene from ab-initio calculations
• Vibrational spectrum and electron-phonon coupling of doped solid picene from first principles
• Density functional calculations of the electronic structure and magnetic properties of the hydrocarbon K3picene superconductor near the metal-insulator transition
• Electronic properties of molecular solids: the peculiar case of solid Picene
• Electronic structure of pristine and K-doped solid picene: Non-rigid-band change and its implication for electron-intramolecular-vibration interaction

Cited by in corpus (15)

• A Perspective on Conventional High-Temperature Superconductors at High Pressure: Methods and Materials
• Charge Transport in Organic Molecular Semiconductors from First Principles: The Band-Like Hole Mobility in Naphthalene Crystal
• Absence of metallicity in K-doped picene: Importance of electronic correlations
• Investigating polaron transitions with polar molecules
• Band gap renormalization, carrier mobilities, and the electron-phonon self-energy in crystalline naphthalene
• Metal Borohydrides as high-$T_c$ ambient pressure superconductors
• A combined experimental and computational study of the pressure dependence of the vibrational spectrum of solid picene C_22H_14
• Atomic forces by quantum Monte Carlo: application to phonon dispersion calculation
• Downfolding electron-phonon Hamiltonians from ab-initio calculations: application to K${}_3$Picene
• Crystal structure search and electronic properties of alkali doped phenanthrene and picene
• Electron-doped organics: Charge-disproportionate insulators and Hubbard-Fröhlich metals
• Correlated Electronic Structures and the Phase Diagram of Hydrocarbon-based Superconductors
• Competing Correlated Insulators in multi-orbital systems coupled to phonons
• Theory of metal-intercalated phenacenes: Why molecular valence 3 is special
• Robust $s\pm$ Superconductivity in a Two-Band Hubbard-Fr{ö}hlich Model of Alkali Doped Organics