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arXiv 1306.2241cond-mat.supr-con
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电子掺杂铜氧化物中的量子临界配对

Quantum-critical pairing in electron-doped cuprates

Yuxuan Wang, Andrey Chubukov

摘要:

本文重新讨论了序动量为(π,π)= 2k_F的反铁磁量子临界点上的自旋介导超导配对问题。这个问题以前曾被一位作者考虑过。然而,后来有人指出,该分析忽略了自旋极化算符的umklapp过程。我们将umklapp条款和重新评估正常状态的自能和临界温度的配对不稳定性。我们证明了自能具有费米液体形式,并得到了准粒子留数Z的重整化、费米速度和费米面的曲率。我们认为这种配对是一个BCS型问题,但我们在BCS理论的基础上又向前进了一步,用前因子计算了临界温度T_c。将结果应用于最佳掺杂附近的电子掺杂铜氧化物,得到了T_c \geq 10 K,与实验结果吻合较好.

英文摘要:

We revisit the problem of spin-mediated superconducting pairing at the antiferromagnetic quantum-critical point with the ordering momentum (π,π) = 2k_F. The problem has been previously considered by one of the authors. However, it was later pointed out that that analysis neglected umklapp processes for the spin polarization operator. We incorporate umklapp terms and re-evaluate the normal state self-energy and the critical temperature of the pairing instability. We show that the self-energy has a Fermi-liquid form and obtain the renormalization of the quasiparticle residue Z, the Fermi velocity, and the curvature of the Fermi surface. We argue that the pairing is a BCS-type problem, but go one step beyond the BCS theory and calculate the critical temperature T_c with the prefactor. We apply the results to electron-doped cuprates near optimal doping and obtain T_c \geq 10 K, which matches the experimental results quite well.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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