权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Quantum electric dipoles: Water molecules in nano-cages of crystals

量子电偶极子：晶体纳米笼中的水分子

基本信息

批准号：
397476507
负责人：
Professor Dr. Hans Peter Büchler
金额：
--
依托单位：
Institut für Theoretische Physik III
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2022-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/397476507?language=en
关键词：
Quantum electric dipoles Water molecules

项目摘要

We investigate quantum electric dipoles realized by H2O molecules confined to nanocages of crystals. Since the isolated molecules do not form hydrogen bonds, they constitute an ideal model of a quantum electric dipole lattice. Tunneling within the nanocage smears out the positions of the protons. We plan to study the energy levels of nano-confined water molecules in dielectric frameworks with different geometries. We use broad-band optical spectroscopy to investigate the rotational and vibrational modes, the interaction with the cage walls and the doping atoms in the structure. Quantum-mechanical simulations within the DFT approach, as well as MD model the systems and develop a deep understanding of how quantum tunneling and fluctuations affect the properties and behavior of the confined electric dipoles. We address the dipolar interaction between the H2O molecules that eventually leads to long-range order and the occurrence of an incipient ferroelectric state of water in beryl. We explore how the anisotropic dipole-dipole coupling forms a 3D cooperative many-body state from the delocalized H2O. Here, low-frequency optical and dielectric investigations are the superior methods. Starting with the prototype beryl, varying the filling can modify the length of dipolar chains; the coupling can be enhanced by pressure. The anisotropic interaction is reflected in the polarization-dependent optical and dielectric response. We study the influence of an external electric field and the possibility of domain wall motion. We then go beyond beryl with its particular triangular ab-lattice and investigate other nano-porous crystals, and, consequently, altered couplings between the confined H2O molecules. This modifies the dipolar interaction strength and anisotropy within the ab-plane. When the c-axis coupling is dominant, chains of electric dipoles are realized; if this coupling becomes inferior, the system may be treated as two-dimensional with a geometry imposed by the crystal lattice. The interplay of quantum tunneling, fluctuation, and frustration among the coupled electric dipoles could provide the possibility to realize a quantum electric dipole liquid and glasses.From the theoretical side, we tackle the problem numerically and analytically. We model water confined in various crystal types and calculate the optical spectra for different filling. We then turn to the influence of temperature, pressure, and electric fields on the thermodynamic properties and incipient ferroelectricity of nano-confined water in beryl. In parallel we analyze the many-body phenomena of the interacting dipole moments including their quantum rotation. We want to understand the phase diagram within mean-field theory and the competition between the slow decay of the dipolar interaction and their anisotropy. These mean-field studies are accompanied by suitable numerical simulations with the goal to link the predictions of the model system to the experimental observations.

研究了水分子在纳米笼中的量子电偶极子。由于孤立的分子不形成氢键，它们构成了量子电偶极晶格的理想模型。纳米笼中的纳米粒子模糊了质子的位置。我们计划研究不同几何形状的介电框架中纳米受限水分子的能级。我们使用宽带光谱来研究旋转和振动模式，与笼壁和结构中的掺杂原子的相互作用。DFT方法中的量子力学模拟以及MD对系统进行建模，并深入了解量子隧穿和波动如何影响受限电偶极子的特性和行为。我们解决的偶极之间的相互作用的水分子，最终导致长程有序和绿柱石中的水的初期铁电状态的发生。我们探讨了各向异性偶极-偶极耦合如何从离域的H2O形成三维合作多体态。在这里，低频光学和介电研究是上级方法。从原型绿柱石开始，改变填充可以改变偶极链的长度;耦合可以通过压力来增强。各向异性相互作用反映在偏振相关的光学和介电响应。我们研究了外加电场的影响和畴壁运动的可能性。然后，我们超越绿柱石与其特定的三角形ab-晶格和调查其他纳米多孔晶体，并因此，改变耦合之间的限制H2O分子。这改变了ab平面内的偶极相互作用强度和各向异性。当c轴耦合占主导地位时，实现电偶极子链;如果这种耦合变得较差，则系统可以被视为具有晶格强加的几何形状的二维系统。耦合电偶极之间的量子隧穿、涨落和挫挫的相互作用为实现量子电偶极液体和玻璃提供了可能。我们模拟了不同晶体类型中的水，并计算了不同填充情况下的光谱。然后，我们转向温度，压力和电场的热力学性质和初期的铁电性的绿柱石纳米承压水的影响。在平行，我们分析了相互作用的偶极矩，包括他们的量子旋转的多体现象。我们想了解平均场理论中的相图，以及偶极相互作用的缓慢衰减与它们的各向异性之间的竞争。这些平均场研究伴随着适当的数值模拟，其目标是将模型系统的预测与实验观测相联系。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Quantum Critical Behavior of Nanoconfined Water Molecules

纳米限制水分子的量子临界行为

DOI：
10.1109/irmmw-thz.2019.8873791
发表时间：
2019
期刊：
2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
影响因子：
0
作者：
E.S. Zhukova;M.A. Belyanchikov;M. Savinov;P. Bednyakov;J. Prokleska;S. Kamba;Z.V. Bedran;V.G. Thomas;V.I. Torgashev;E. Uykur;M. Dressel;B.P. Gorshunov
通讯作者：
B.P. Gorshunov

Fingerprints of Critical Phenomena in a Quantum Paraelectric Ensemble of Nanoconfined Water Molecules.

DOI：
10.1021/acs.nanolett.2c00638
发表时间：
2022-04
期刊：
Nano letters
影响因子：
10.8
作者：
M. Belyanchikov;M. Savinov;P. Proschek;J. Prokleška;E. Zhukova;V. Thomas;Z. Bedran;F. Kadlec
通讯作者：
M. Belyanchikov;M. Savinov;P. Proschek;J. Prokleška;E. Zhukova;V. Thomas;Z. Bedran;F. Kadlec

Effect of hydrostatic pressure on the quantum paraelectric state of dipolar coupled water molecular network

DOI：
10.1103/physrevresearch.4.023205
发表时间：
2022-06
期刊：
Physical Review Research
影响因子：
4.2
作者：
Y. T. Chan;E. Uykur;M. Belyanchikov;M. Dressel;V. Abalmasov;V. Thomas;E. Zhukova;B. Gorshunov
通讯作者：
Y. T. Chan;E. Uykur;M. Belyanchikov;M. Dressel;V. Abalmasov;V. Thomas;E. Zhukova;B. Gorshunov

Dielectric ordering of water molecules arranged in a dipolar lattice