Magnetic oscillations and quasiparticle band structure in the mixed state of type-II superconductors

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.5927· OSTI ID:6583672

Norman, M R ^[1]; MacDonald, A H ^[2]; Akera, H ^[3]

---

1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States)
3. Faculty of Engineering, Hokkaido University, Sapporo 060 (Japan)

We consider magnetic oscillations due to Landau quantization in the mixed state of type-II superconductors. Our work is based on a previously developed formalism which allows the mean-field gap equations of the Abrikosov state to be conveniently solved in a Landau-level representation. We find that the quasiparticle band structure changes qualitatively when the pairing self-energy becomes comparable to the Landau-level separation. For small pairing self-energies, Landau-level mixing due to the superconducting order is weak and magnetic oscillations survive in the superconducting state although they are damped. We find that the width of the quasiparticle Landau levels in this regime varies approximately as [Delta][sub 0][ital n][sub [mu]][sup [minus]1/4] where [Delta][sub 0] is proportional to the magnitude of the order parameter and [ital n][sub [mu]] is the Landau-level index at the Fermi energy. For larger pairing self-energies, the lowest energy quasiparticle bands occur in pairs which are nearly equally spaced from each other and evolve with weakening magnetic field toward the bound states of an isolated vortex core. These bands have a weak magnetic field dependence and magnetic oscillations vanish rapidly in this regime. We discuss recent observations of the de Haas--van Alphen effect in the mixed state of several type-II superconductors in light of our results.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6583672
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 51:9; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BINDING ENERGY
DE HAAS-VAN ALPHEN EFFECT
ELECTRONIC STRUCTURE
ENERGY
MAGNETIC PROPERTIES
MIXED STATE
OSCILLATIONS
PAIRING ENERGY
PHYSICAL PROPERTIES
QUANTIZATION
QUASI PARTICLES
SUPERCONDUCTORS
TYPE-II SUPERCONDUCTORS