2005/04/29 by Biao Jin, Gang Su, Qing‐Rong Zheng +1
Physics and Astronomy · #Condensed matter physics #Critical exponent #Ferromagnetism #Phase (matter) #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum critical point #Quantum mechanics #Quantum phase transition #Rare-earth and actinide compounds #Superconductivity #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.71.144514
published as Phys. Rev. B 71, 144514 (2005) · 5 pages, 4 figures, Phys. Rev. B 71, 144514 (2005)
openalex publication_date 2005/04/29 · arxiv created 2005/09/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
First- and second-order phase transitions, Fulde-Ferrel (FF) inhomogeneous superconducting (SC) state, and quantum criticality in ferromagnet/superconductor/ferromagnet double-tunnel junctions are investigated. For the antiparallel alignment of magnetizations, it is shown that a first-order phase transition from the homogeneous BCS state to the inhomogeneous FF state occurs at a certain bias voltage V*, while the transitions from the BCS state and the FF state to the normal state at Vc are of the second-order. A phase diagram for the central superconductor is presented. In addition, a quantum critical point (QCP), VQCP, is identified. It is uncovered that near the QCP, the SC gap, the chemical potential shift induced by the spin accumulation, and the difference of the free energies between the SC and the normal states vanish as \ensuremath|V\ensuremath-VQCP\ensuremath|^z\ensuremathν with the quantum critical exponents z\ensuremathν=(1)/(2), 1, and 2, respectively. The tunnel conductance and magnetoresistance are also discussed.