Competition between the superconductivity and nematic order in the high-Tc superconductor
Competition between the superconductivity and nematic order in the high-Tc superconductor
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DOI：
10.1088/1367-2630/15/7/073039
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发表时间：
2012-05
影响因子：
3.3
通讯作者：
Jing Wang;Guo-Zhu Liu
中科院分区：
文献类型：
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作者：
Jing Wang;Guo-Zhu Liu
我们研究了d波超导性和高Tc超导体中的π阶之间的竞争，并研究了无带隙费米自由度所起的作用。除了与超导序参量的竞争相互作用外，超导序参量与无带隙节状准粒子有很强的耦合。这两种相互作用的相互作用的重整化群方法进行了分析。在完全忽略费米子自由度的情况下，两个玻色子序参量之间的竞争相互作用是强烈相关的，并可能导致失控行为。然而，一旦考虑到费米子的动力学，这些性质就从根本上改变了。在极端费米子速度各向异性发生的二次量子临界点，超导和二次参数相互解耦。因此，相变是连续的，并且d波超导性可以与超有序均匀共存。这些结果表明，无带隙费米子可以发挥重要的作用，并应仔细包括在竞争订单的理论描述。
We investigate the competition between the d-wave superconductivity and the nematic order in the high-Tc superconductor and examine the role played by the gapless fermionic degrees of freedom. Apart from the competitive interaction with the superconducting order parameter, the nematic order parameter couples strongly to gapless nodal quasiparticles. The interplay of these two kinds of interactions is analyzed by means of the renormalization group method. In case the fermionic degrees of freedom are entirely neglected, the competitive interaction between the two bosonic order parameters is strongly relevant and can lead to runaway behavior. However, these properties are fundamentally changed once the dynamics of the fermions are taken into account. At the nematic quantum critical point where an extreme fermion velocity anisotropy occurs, the superconducting and nematic order parameters are decoupled from each other. Consequently, the phase transitions are continuous and the d-wave superconductivity can coexist with the nematic order homogeneously. These results indicate that the gapless fermions can play an important role and should be carefully included in the theoretical description of competing orders.