Softening of Spin-Wave Stiffness near the Ferromagnetic Phase Transition in Diluted Magnetic Semiconductors
نویسنده
چکیده
ing momentum p from ζ(q, ω) in equation (14) results to a relation 〈〈c†p+q,↑cp,↓;S (0, 0)〉〉 = cJ 2 〈c†p,↓cp,↓〉 − 〈c † p+q,↑cp+q,↑〉 ω − εp + εp+q − cJ〈Sz〉 ×G(q, ω). (15) Combining equations (10) and (14) results to a closed form of Green’s function equation G(q, ω), (ω − cJ〈σ〉 + cJ 2 〈S〉 ∑ p 〈c†p,↓cp,↓〉 − 〈c † p+q,↑cp+q,↑〉 ω − εp + εp+q − cJ〈Sz〉 )
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