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arXiv 0908.2245cond-mat.str-elcond-mat.mes-hall
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简并Anderson杂质模型的局域矩方法

A local moment approach to the degenerate Anderson impurity model

Martin R. Galpin, Anne B. Gilbert, David E. Logan

摘要:

将局域矩方法推广到轨道简并的[SU(2N)] Anderson杂质模型(AIM)。单粒子动力学是在整个能量尺度范围内获得的,这里集中在强相关制度中的粒子-空穴对称性,其中现场库仑相互作用导致具有纠缠自旋和轨道自由度的多体近藤物理。该方法捕获的Hubbard卫星的多体加宽,恢复正确的指数消失的近藤规模的所有N,其普遍的标度谱被发现是非常好的协议与数值重整化群(NRG)的结果。特别是高频对数衰减的标度谱,在这里得到的封闭形式为任意N,基本上完全符合现有的数字从NRG。还讨论了各向异性库仑相互作用的一个特殊情况,其中模型代表N个“电容耦合”SU(2)AIM系统。在这里,该模型通常以两个低能量尺度为特征,它们之间的交叉可以直接在其动态中看到。

英文摘要:

The local moment approach is extended to the orbitally-degenerate [SU(2N)] Anderson impurity model (AIM). Single-particle dynamics are obtained over the full range of energy scales, focussing here on particle-hole symmetry in the strongly correlated regime where the onsite Coulomb interaction leads to many-body Kondo physics with entangled spin and orbital degrees of freedom. The approach captures many-body broadening of the Hubbard satellites, recovers the correct exponential vanishing of the Kondo scale for all N, and its universal scaling spectra are found to be in very good agreement with numerical renormalization group (NRG) results. In particular the high-frequency logarithmic decays of the scaling spectra, obtained here in closed form for arbitrary N, coincide essentially perfectly with available numerics from the NRG. A particular case of an anisotropic Coulomb interaction, in which the model represents a system of N `capacitively-coupled' SU(2) AIMs, is also discussed. Here the model is generally characterised by two low-energy scales, the crossover between which is seen directly in its dynamics.

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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