Switching effects in superconductor/ferromagnet/superconductor graphene junctions

• 作 者: 李晓薇 刘丹 鲍艳辉
• 机 构: School of Physics and Electronic Electrical Engineering and Jiangsu Key Laboratory for Chemistry of
• 出 处: Chinese Physics B
• 发表日期: 2013年12期
• 关键词: superconductor junction coexistence Switching length Dirac minima vicinity brief

The Josephson effect in the superconductor/ferromagnet/superconductor(SFS) graphene Josephson junction is studied using the Dirac Bogoliubov-de Gennes(DBdG) formalism. It is shown that the SFS graphene junction drives 0–π transition with the increasing of p=h0L/vFhˉ, which captures the effects of both the exchange field and the length of the junction; the spin-down current is dominant. The 0 state is stable for p < pc(critical value pc ≈ 0.80) and theπ state is stable for p > pc, where the free energy minima are at φg= 0 and φg= π, respectively. The coexistence of the 0 and π states appears in the vicinity of pc. The Josephson effect in the superconductor / ferromagnet / superconductor (SFS) graphene Josephson junction is studied using the Dirac Bogoliubov-de Gennes (DBdG) formalism. It shows that the SFS graphene junction drives 0-π transition with the increasing of p = h0L / vFhˉ, which captures the effects of both the exchange field and the length of the junction; the spin-down current is dominant. The 0 state is stable for p pc, where the free energy minima are at φg = 0 and φg = π, respectively. The coexistence of the 0 and π states appears in the vicinity of pc.