论文标题
边界三链模型中的金属绝缘体过渡
Metal-insulator transition in a boundary three chain model
论文作者
论文摘要
我们通过考虑三个耦合的哈伯德链在线性限制电位中研究大量绝缘体的边界物理学。在Hartree-fock近似中，即使在限制电势的大坡度处，粒子孔对称点处的基态仍在隔离。相比之下，通过持续化和RG方法的结合来考虑量子波动和相关性，我们发现总是有无间隙偶极模式，但这并不促进有限的可压缩性。此外，当增加一半填充物的狭窄电势的斜率时，我们发现绝缘状态和金属状态之间的量子相变，表明形成了非探针起源的柔软边缘状态。远离半填充，发生了类似的过渡。
We study the boundary physics of bulk insulators by considering three coupled Hubbard chains in a linear confining potential. In the Hartree-Fock approximation, the ground state at and slightly off the particle-hole symmetric point remains insulating even at large slopes of the confining potential. By contrast, accounting for quantum fluctuations and correlations through a combination of bosonization and RG methods, we find that there is always a gapless dipole mode, but it does not contribute to a finite compressibility. Moreover, when increasing the slope of the confining potential at half filling, we find a quantum phase transition between an insulating and a metallic state, indicating the formation of a soft edge state of non-topological origin. Away from half filling, a similar transition takes place.
