非常规超导的平均场理论
发布时间：2018-08-28 20:20
【摘要】：本论文用平均场理论研究非常规超导体的物理性质。我们用平均场方法自洽地求解非常规超导的能隙函数,并进一步算出比热和伦敦穿透深度,以此来辨别超导中可能的配对方式。能隙函数的自洽方程是通过对平均场Hamiltonian做Bogoliubov变换得到的,我们求解该自洽方程,得到Bogoliubov准粒子的能谱。在此基础上得到超导比热和弱磁场时的伦敦穿透深度。通过比较低温时比热和穿透深度与温度的幂次关系,就能推断超导电子的配对方式。在论文的最后,我们用3带Hubbard模型研究最近发现的一类超导体A2Cr3As3,发现其中f-wave的自旋三重态配对占主导。
[Abstract]:In this paper, the physical properties of unconventional superconductors are studied by means of the mean field theory. We use the mean field method to solve the energy gap function of the unconventional superconducting and further calculate the specific heat and the London penetration depth to identify the possible pairings in superconductivity. The self-consistent equation of the energy gap function is obtained by the Bogoliubov transformation of the mean field Hamiltonian. We solve the self-consistent equation and obtain the energy spectrum of the Bogoliubov quasiparticle. On this basis, the London penetration depth of superconducting specific heat and weak magnetic field is obtained. By comparing the power relationship between specific heat and penetration depth and temperature at low temperature, the matching mode of superconducting electrons can be inferred. At the end of the paper, we use the 3-band Hubbard model to study a class of recently discovered superconductors A _ 2Cr _ 3As _ 3, and find that the spin triplet pairing of f-wave is dominant.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM26
本文编号：2210504
[Abstract]:In this paper, the physical properties of unconventional superconductors are studied by means of the mean field theory. We use the mean field method to solve the energy gap function of the unconventional superconducting and further calculate the specific heat and the London penetration depth to identify the possible pairings in superconductivity. The self-consistent equation of the energy gap function is obtained by the Bogoliubov transformation of the mean field Hamiltonian. We solve the self-consistent equation and obtain the energy spectrum of the Bogoliubov quasiparticle. On this basis, the London penetration depth of superconducting specific heat and weak magnetic field is obtained. By comparing the power relationship between specific heat and penetration depth and temperature at low temperature, the matching mode of superconducting electrons can be inferred. At the end of the paper, we use the 3-band Hubbard model to study a class of recently discovered superconductors A _ 2Cr _ 3As _ 3, and find that the spin triplet pairing of f-wave is dominant.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM26
【相似文献】
相关期刊论文 前4条
1 边海琴;孙爱民;朱海滨;;LuNi_2B_2C、YNi_2B_2C超导参量的研究[J];西北师范大学学报(自然科学版);2008年06期
2 岳小萍;;统计性超导电子对密度与温度无关[J];新乡学院学报(自然科学版);2011年01期
3 公丕锋;苏希玉;王建阳;郝清海;;在二带京兹堡朗道理论下MgB_2的超导参量的研究[J];低温与超导;2006年01期
4 ;[J];;年期
相关会议论文 前1条
1 余铁军;张雪霞;高葆新;吴培亨;;超导Fresne1公式及表面阻抗Zs的研究[A];1995年全国微波会议论文集（下册）[C];1995年
相关硕士学位论文 前1条
1 何洋;非常规超导的平均场理论[D];浙江大学;2015年
，本文编号：2210504
本文链接：https://www.wllwen.com/kejilunwen/cailiaohuaxuelunwen/2210504.html
