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arXiv 1009.5587cond-mat.str-elhep-th
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一维莫特绝缘体局域态密度和电荷密度波态的边界效应

Boundary effects on the local density of states of one-dimensional Mott insulators and charge density wave states

Dirk Schuricht, Fabian H. L. Essler, Akbar Jaefari, Eduardo Fradkin

摘要:

本文研究了硬壁边界条件下自旋带隙的一维电荷密度波(CDW)态和莫特绝缘体的局域态密度(LDOS)。我们用场论方法计算了低能极限下边界对单粒子格林函数的贡献,并从时间和空间的傅里叶变换的角度对其进行了分析。在CDW情况下的边界LDOS表现出在动量2kF处的奇异性,这指示在杂质处的CDW阶的钉扎。我们进一步观察到几个分散功能的频率以上的自旋间隙,这提供了一个特征签名的自旋-电荷分离。这表明,边界LDOS可以用来推断底层体系统的属性。在存在边界磁场时,出现了局限于边界的中间带隙态。我们调查的LDOS中的这种绑定状态的签名。我们讨论了我们的研究结果的影响STM实验上的准一维系统,如两个腿梯形材料,如Sr 14 Cu 24 O 41。通过交换电荷扇区和自旋扇区的作用,我们的所有结果直接推广到一维莫特绝缘体的情形。

英文摘要:

We determine the local density of states (LDOS) for spin-gapped one-dimensional charge density wave (CDW) states and Mott insulators in the presence of a hard-wall boundary. We calculate the boundary contribution to the single-particle Green function in the low-energy limit using field theory techniques and analyze it in terms of its Fourier transform in both time and space. The boundary LDOS in the CDW case exhibits a singularity at momentum 2kF, which is indicative of the pinning of the CDW order at the impurity. We further observe several dispersing features at frequencies above the spin gap, which provide a characteristic signature of spin-charge separation. This demonstrates that the boundary LDOS can be used to infer properties of the underlying bulk system. In presence of a boundary magnetic field mid-gap states localized at the boundary emerge. We investigate the signature of such bound states in the LDOS. We discuss implications of our results on STM experiments on quasi-1D systems such as two-leg ladder materials like Sr14Cu24O41. By exchanging the roles of charge and spin sectors, all our results directly carry over to the case of one-dimensional Mott insulators.

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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