Collective excitations and the crossover from Cooper pairs to composite bosons in the attractive Hubbard model

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.5087· OSTI ID:7276354

Belkhir, L ^[1]; Randeria, M ^[2]

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1. Department of Physics, State University of New York, Stony Brook, New York 11794-3800 (United States)
2. Argonne National Laboratory, Materials Science Division 223, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

Motivated by the short coherence length of the high-temperature superconductors, we study in the negative-{ital U} Hubbard model the crossover from Cooper pairs for {ital U}{much lt}{ital t} to composite bosons for {ital U}{much gt}{ital t}. We compute the collective-mode spectrum using a generalized random-phase-approximation analysis within the equations-of-motion formalism. We find a smooth evolution of the Anderson mode for weak coupling into the Bogoliubov sound mode for hard-core bosons.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7276354
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 45:9; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSONS
COLLECTIVE EXCITATIONS
COOPER PAIRS
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITATION
HIGH-TC SUPERCONDUCTORS
MEAN-FIELD THEORY
RANDOM PHASE APPROXIMATION
SPECTRA
SUPERCONDUCTORS