Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milano, Italy.
Department of Physics, The College of William and Mary, Williamsburg, Virginia 23187, USA.
Phys Rev Lett. 2016 Apr 1;116(13):135302. doi: 10.1103/PhysRevLett.116.135302.
We compute the zero-temperature dynamical structure factor of one-dimensional liquid ^{4}He by means of state-of-the-art quantum Monte Carlo and analytic continuation techniques. By increasing the density, the dynamical structure factor reveals a transition from a highly compressible critical liquid to a quasisolid regime. In the low-energy limit, the dynamical structure factor can be described by the quantum hydrodynamic Luttinger-liquid theory, with a Luttinger parameter spanning all possible values by increasing the density. At higher energies, our approach provides quantitative results beyond the Luttinger-liquid theory. In particular, as the density increases, the interplay between dimensionality and interaction makes the dynamical structure factor manifest a pseudo-particle-hole continuum typical of fermionic systems. At the low-energy boundary of such a region and moderate densities, we find consistency, within statistical uncertainties, with predictions of a power-law structure by the recently developed nonlinear Luttinger-liquid theory. In the quasisolid regime, we observe a novel behavior at intermediate momenta, which can be described by new analytical relations that we derive for the hard-rods model.
我们通过最先进的量子蒙特卡罗和解析延拓技术计算了一维液态 ^{4}He 的零温动力学结构因子。随着密度的增加，动力学结构因子揭示了从高压缩临界液体到准固体态的转变。在低能极限下，动力学结构因子可以用量子流体力学 Luttinger-liquid 理论来描述，通过增加密度，Luttinger 参数可以跨越所有可能的值。在更高的能量下，我们的方法提供了超越 Luttinger-liquid 理论的定量结果。特别是，随着密度的增加，维度和相互作用之间的相互作用使得动力学结构因子表现出典型的费米子系统的赝粒子-空穴连续体。在这种区域的低能边界和中等密度下，我们在统计不确定性内找到了与最近发展的非线性 Luttinger-liquid 理论所预测的幂律结构的一致性。在准固体态，我们在中间动量处观察到一种新的行为，我们可以用我们为硬棒模型推导的新的解析关系来描述这种行为。
