论文标题
准粒子激发的通用rényi熵
Universal Rényi Entropy of Quasiparticle Excitations
论文作者
论文摘要
多体间隙系统中准粒子激发的rényi熵显示出了显着的通用图片,可以通过将半经典论证与(in)区分性的量子效应结合结合来部分理解。通用的rényi熵独立于模型,准颗粒臂和子系统的连接性。在这封信中,我们精确地计算了多体gaped式费米子,玻色子和XY链中准粒子激发的单间隔和双间隙rényi熵。我们发现,具有不同动量的准粒子的激发态中通用的rényi熵做出了其他贡献。附加项在费米子和骨链中是不同的,取决于准粒子的动量差异,并且对于单个间隔和双间隔而言是不同的。我们将分析性的rényi熵推导出极度差的极限,只要模型的内在相关长度或准粒子的所有de broglie波长很小,就可以完全匹配数值结果。当任何一对不同的准颗粒的动量差异很小时,其他术语不可忽略。相反,当每对不同的准粒子的动量的差异很大时,可以忽略其他术语。通用的单间隔rényi熵及其在XY链中的附加术语与费米子链中的术语相同,而双间隔的通用rényi熵及其附加项则不同,因为XY链的本地自由度是Pauli矩阵的当地自由度,而不是Pauli Matrices无旋转的效仿。我们认为,派生的公式具有通用属性,并且可以适用于与此处讨论的模型更广泛的模型。
The Rényi entropies of quasiparticle excitations in the many-body gapped systems show a remarkable universal picture which can be understood partially by combination of a semiclassical argument with the quantum effect of (in)distinguishability. The universal Rényi entropies are independent of the model, the quasiparticle momenta, and the connectedness of the subsystem. In this letter we calculate exactly the single-interval and double-interval Rényi entropies of quasiparticle excitations in the many-body gapped fermions, bosons, and XY chains. We find additional contributions to the universal Rényi entropy in the excited states with quasiparticles of different momenta. The additional terms are different in the fermionic and bosonic chains, depend on the momentum differences of the quasiparticles, and are different for the single interval and the double interval. We derive the analytical Rényi entropy in the extremely gapped limit, matching perfectly the numerical results as long as either the intrinsic correlation length of the model or all the de Broglie wavelengths of the quasiparticles are small. When the momentum difference of any pair of distinct quasiparticles is small, the additional terms are non-negligible. On the contrary, when the difference of the momenta of each pair of distinct quasiparticles is large, the additional terms could be neglected. The universal single-interval Rényi entropy and its additional terms in the XY chain are the same as those in the fermionic chain, while the universal Rényi entropy of the double intervals and its additional terms are different, due to the fact that the local degrees of freedom of the XY chain are the Pauli matrices not the spinless fermions. We argue that the derived formulas have universal properties and can be applied for a wider range of models than those discussed here.