论文标题
使用DFT近似量子热力学特性
Approximating quantum thermodynamic properties using DFT
论文作者
论文摘要
量子技术的制造，利用和效率取决于对量子热力学特性的良好理解。多体系统通常用作这些量子设备的硬件，但是粒子之间的相互作用使相关计算的复杂性随系统尺寸呈指数增长。在这里，我们探索并系统地将“简单”和“混合”近似值与基于静态密度功能理论概念构建的平均工作和熵变化进行了比较。这些近似值在计算上很便宜，可以应用于大型系统。考虑到驱动的一维哈伯德链，我们体现了他们的体现，并表明，对于“简单”近似值和低至中等温度，考虑到良好的Kohn-Sham Hamiltonian来近似驾驶Hamiltonian，这是值得的。我们的结果证实了一种“混合”方法，需要对系统的最初状态进行良好的近似，并且需要进行最终状态。当驾驶哈密顿量没有增加多体效应时，这种方法应特别有效。
The fabrication, utilisation, and efficiency of quantum technologies rely on a good understanding of quantum thermodynamic properties. Many-body systems are often used as hardware for these quantum devices, but interactions between particles make the complexity of related calculations grow exponentially with the system size. Here we explore and systematically compare `simple' and `hybrid' approximations to the average work and entropy variation built on static density functional theory concepts. These approximations are computationally cheap and could be applied to large systems. We exemplify them considering driven one-dimensional Hubbard chains and show that, for `simple' approximations and low to medium temperatures, it pays to consider a good Kohn-Sham Hamiltonian to approximate the driving Hamiltonian. Our results confirm that a `hybrid' approach, requiring a very good approximation of the initial and, for the entropy, final states of the system, provides great improvements. This approach should be particularly efficient when many-body effects are not increased by the driving Hamiltonian.
