Fermi surface of superconducting LaFePO determined by quantum oscillations

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Nature Physics

OSTI ID:960578

Mcdonald, Ross D ^[1]; Coldea, A I ^[2]; Fletcher, J D ^[2]; Carrington, A ^[2]; Bangura, A F ^[2]; Hussey, N E ^[2]; Analytis, J G ^[3]; Chu, J-h ^[3]; Erickson, A S ^[3]; Fisher, I R ^[3]

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1. Los Alamos National Laboratory
2. BRISTOL UNIV
3. STANFORD UNIV

The recent discovery of superconductivity in ferrooxypnictides, which have a maximum transition temperature intermediate between the two other known high temperature superconductors MgB{sub 2} and the cuprate family, has generated huge interest and excitement. The most critical issue is the origin of the pairing mechanism. Whereas superconductivity in MgB{sub 2} has been shown to arise from strong electron-phonon coupling, the pairing glue in cuprate superconductors is thought by many to have a magnetic origin. The oxypnictides are highly susceptible to magnetic instabilities, prompting analogies with cuprate superconductivity. Progress on formulating the correct theory of superconductivity in these materials will be greatly aided by a detailed knowledge of the Fermi surface parameters. Here we report for the first time extensive measurements of quantum oscillations in a Fe-based superconductor, LaFePO, that provide a precise calliper of the size and shape of the Fermi surface and the effective masses of the relevant charge carriers. Our results show that the Fermi surface is composed of nearly-nested electron and hole pockets in broad agreement with the band-structure predictions but with significant enhancement of the quasiparticle masses. The correspondence in the electron and hole Fermi surface areas provides firm experimental evidence that LaFePO, whilst unreconstructed, lies extremely close to a spin-density-wave instability, thus favoring models that invoke such a magnetic origin for high-temperature superconductivity in oxypnictides.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960578
• Report Number(s): LA-UR-08-05342; LA-UR-08-5342; TRN: US1002074
• Journal Information: Nature Physics, Journal Name: Nature Physics
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGE CARRIERS
CUPRATES
ELECTRON-PHONON COUPLING
ELECTRONS
FERMI LEVEL
HOLES
INSTABILITY
IRON COMPOUNDS
LANTHANUM COMPOUNDS
MATERIALS
OSCILLATIONS
OXYGEN
PHOSPHORUS COMPOUNDS
PNICTIDES
SHAPE
SIZE
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE RANGE 0400-1000 K
TRANSITION TEMPERATURE