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arXiv 2302.06305quant-phcond-mat.str-elhep-lathep-th
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一维自由费米子晶格模型的复杂度增长

Complexity growth for one-dimensional free-fermionic lattice models

S. Aravinda, Ranjan Modak

AI总结:

本文研究一维自由费米子晶格模型中量子复杂度上下界的时间演化,发现短程模型下界线性增长后饱和,长程跳跃模型呈亚线性增长,而上界在更长时间内保持线性增长并最终饱和。

摘要:

复杂度在量子计算与量子模拟中扮演着非常重要的角色,它作为实现一个幺正线路所需的最少门数的一种度量。我们研究非相互作用费米子的一维晶格模型幺正动力学的复杂度下界 [Eisert, Phys. Rev. Lett. 127, 020501 (2021)]。我们利用准粒子形式化方法解析地发现,对于短程紧束缚哈密顿量,该下界随时间线性增长,随后趋于饱和。我们给出数值证据表明,对于初始 Néel 态,无论是紧束缚哈密顿量还是长程跳跃模型,该下界都达到最大值。然而,对于后者,下界的增长随时间呈亚线性,这与短程模型中观察到的线性增长形成对比。我们还计算了非相互作用费米子晶格模型中复杂度的上界,该上界即使在下界饱和时间之后仍随时间线性增长,最终也趋于饱和。

英文摘要:

Complexity plays a very important part in quantum computing and simulation where it acts as a measure of the minimal number of gates that are required to implement a unitary circuit. We study the lower bound of the complexity [Eisert, Phys. Rev. Lett. 127, 020501 (2021)] for the unitary dynamics of the one-dimensional lattice models of non-interacting fermions. We find analytically using quasiparticle formalism, the bound grows linearly in time and followed by a saturation for short-ranged tight-binding Hamiltonians. We show numerical evidence that for an initial Neel state the bound is maximum for tight-binding Hamiltonians as well as for the long-range hopping models. However, the increase of the bound is sub-linear in time for the later, in contrast to the linear growth observed for short-range models. The upper bound of the complexity in non-interacting fermionic lattice models is calculated, which grows linearly in time even beyond the saturation time of the lower bound, and finally, it also saturates.

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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