Fluctuating stripes in strongly correlated electron systems and the nematic-smectic quantum phase transition
Fluctuating stripes in strongly correlated electron systems and the nematic-smectic quantum phase transition
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强相关电子系统中的波动条纹和向列-近晶量子相变
DOI：
10.1103/physrevb.78.085124
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发表时间：
2008
影响因子：
3.7
通讯作者：
E. Fradkin
中科院分区：
文献类型：
--
作者：
K. Sun;Benjamin M. Fregoso;M. Lawler;E. Fradkin
我们根据与费米子准粒子耦合的有序参数理论讨论了量子向列金属态到电子金属近晶态之间的量子相变。研究了相称和不相称近晶（或条纹）情况。接近量子临界点（QCP）时，向列相的涨落谱具有低能量的“涨落条纹”。我们研究了量子临界行为，并发现证据表明，与经典情况相反，向列相和近晶相之间的规范类型耦合在此 QCP 中是无关紧要的。还研究了电子近晶（或条带）相的集体模式。对于具有完全旋转对称性的模型和具有离散点群对称性的基础晶格的系统，以微扰方式研究了低能玻色子模式对费米子准粒子的影响。我们发现，在向列-近晶临界点，由于临界近晶涨落，费米表面上几个点附近的费米子准粒子的动力学（围绕这些点进行重构）不受朗道费米液体理论控制。另一方面，近晶相中的准粒子表现出费米液体行为。我们还详细分析了接近 QCP（波动条纹区）的电子向列相和电子近晶相的动力学磁化率。
We discuss the quantum phase transition between a quantum nematic metallic state to an electron metallic smectic state in terms of an order-parameter theory coupled to fermionic quasiparticles. Both commensurate and incommensurate smectic (or stripe) cases are studied. Close to the quantum critical point (QCP), the spectrum of fluctuations of the nematic phase has low-energy ``fluctuating stripes''. We study the quantum critical behavior and find evidence that, contrary to the classical case, the gauge-type of coupling between the nematic and smectic is irrelevant at this QCP. The collective modes of the electron smectic (or stripe) phase are also investigated. The effects of the low-energy bosonic modes on the fermionic quasiparticles are studied perturbatively, for both a model with full rotational symmetry and for a system with an underlying lattice, which has a discrete point group symmetry. We find that at the nematic-smectic critical point, due to the critical smectic fluctuations, the dynamics of the fermionic quasiparticles near several points on the Fermi surface, around which it is reconstructed, are not governed by a Landau Fermi liquid theory. On the other hand, the quasiparticles in the smectic phase exhibit Fermi liquid behavior. We also present a detailed analysis of the dynamical susceptibilities in the electron nematic phase close to this QCP (the fluctuating stripe regime) and in the electronic smectic phase.