Deviations from Fermi-liquid behavior above {ital T}{sub {ital c}} in 2D short coherence length superconductors

Journal Article · Mon Jul 10 04:00:00 EDT 1995 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.75.312· OSTI ID:76564

Trivedi, N; Randeria, M ^[1]

---

1. Materials Science Division 223, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

We show that there are qualitative differences between the temperature dependence of the spin and charge correlations in the normal state of the 2D attractive Hubbard model using quantum Monte Carlo simulations. The one-particle density of states shows a pseudogap above {ital T}{sub {ital c}} with a depleted {ital N}(0) with decreasing {ital T}. The susceptibility {chi}{sub {ital s}} and the low frequency spin spectral weight track {ital N}(0), which explains the spin-gap scaling: 1/{ital T}{sub 1}{ital T}{similar_to}{chi}{sub {ital s}}({ital T}). However, collective excitations contribute to the charge channel, and the compressibility {ital dn}/{ital d}{mu} is {ital T} independent. This anomalous ``spin-charge separation`` is shown to exist even at intermediate {vert_bar}{ital U}{vert_bar} where the momentum distribution {ital n}(k) gives evidence for a degenerate Fermi system.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 76564
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 2 Vol. 75; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
CORRELATION FUNCTIONS
ELECTRONIC STRUCTURE
ENERGY DENSITY
ENERGY GAP
FERMI GAS
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
MONTE CARLO METHOD
SUPERCONDUCTIVITY