在周期正方形和立方格子上,针对粗的能量-景观旋转镜的张量网络的超优化近似收缩
Adil A Gangat1,2, Johnnie Gray2
1Physics & Informatics Laboratories, NTT Research, Inc., Sunnyvale, California 94085, USA.
Physical review. E
|February 7, 2025
概括
这项研究扩展了张量网络方法,以找到平面几何之外的低能自旋玻璃配置. 该方法在复杂的能源环境中显示出有希望的准确性,有助于组合优化.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 计算物理 计算物理
- 统计力学 统计力学
背景情况:
- 在旋转玻璃中找到低能量的配置对于组合优化和基本科学至关重要.
- 传统的搜索启发学与含有众多局部最小值的崎的能量景观作斗争.
- 张量网络收缩为采样博尔兹曼分布提供了一个有希望的替代方案,独立于平面几何形状的景观粗性.
研究的目的:
- 为了研究张量网络收缩方法的扩展,用于超越平面几何形状的旋转眼镜.
- 评估非平面旋转玻璃系统中超优化的近似张量网络收缩的有效性.
- 评估这种方法对各种格子类型和系统大小的计算复杂性和准确性.
主要方法:
- 利用了超优化的近似张量网络收缩.
- 在定期方形和立方格的Ising旋转玻璃上进行了测试,这些玻璃是通过种植瓦产生的.
- 分析了不同系统大小 (高达2304次旋转) 和键层尺寸的性能.
- 与最佳解决方案相比,测量的相对能量误差.
主要成果:
- 在最粗的实例中,以4的键位维度实现了~1% (方格格子) 和~10% (立方格子) 的平均相对能量误差.
- 为不那么坚固的实例找到最佳或接近最佳的解决方案.
- 对于一个固定债券维度的系统大小,证明了二次时间复杂性.
结论:
- 超优化的张量网络收缩对于平面几何之外的旋转眼镜是有效的.
- 这种方法提供了一条可行的途径,用于解决崎的能源景观中复杂的优化问题.
- 基于张量网络的优化的未来发展具有显著的潜力,超越了二进制和双体模型.
相关概念视频
Sequence Networks of Rotating Machines
91
A Y-connected synchronous generator, grounded through a neutral impedance, is designed to produce balanced internal phase voltages with only positive-sequence components. The generator's sequence networks include a source voltage that is exclusively in the positive-sequence network. The sequence components of line-to-ground voltages at the generator terminals illustrate this configuration.
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...
91
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
946
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
946
Spin–Spin Coupling Constant: Overview
863
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
863
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.0K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.0K
¹H NMR: Interpreting Distorted and Overlapping Signals
998
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
998
Maxwell-Boltzmann Distribution: Problem Solving
1.4K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
1.4K


