We study the equilibrium arrangements of polarization vortices in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices by means of second-principles simulations. We find that, at low temperatures, polarization vortices organize in a regular arrangement in which clockwise and counter-clockwise vortices alternate positions, leading to a crystal-like structure with well defined handedness. This chiral crystal melts at a critical temperature $T_\mathrm{M}$ into a chiral liquid, where long-range order is lost but handedness is preserved. At even higher temperatures, $T_\mathrm{C}$, a second phase transition occurs, at which the chiral liquid of polarization vortices loses its handedness. Both phase transitions can be readily identified by the adequate choices of order parameters.
Unconventional crystallization pathway bypassing the intermediate cubic phase in phase-change superlattices
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University（吉林大学电子科学与工程学院集成光电子学国家重点实验室）；School of Integrated Circuits, Huazhong University of Science and Technology（华中科技大学集成电路学院）；Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute（伦斯勒理工学院物理、应用物理和天文学系）
Complex polar superstructure controlled thermal conductivity in ferroelectric PbTiO3/SrTiO3 superlattices
Universidade de Santiago de Compostela（圣地亚哥-德孔波斯特拉大学）；Universidad Rey Juan Carlos（胡安卡洛斯国王大学）；Universitat de Barcelona（巴塞罗那大学）；Catalan Institute of Nanoscience and Nanotechnology (ICN2)（加泰罗尼亚纳米科学与技术研究所）；ALBA Synchrotron Light Facility（阿尔巴同步辐射光源设施）
On the melting of the nanocrystalline vortex matter in high-temperature superconductors
对高各向异性高温超导体Bi $_2$ Sr $_2$ CaCu $_2$ O $_8$中的涡旋物质进行了多能级蒙特卡罗模拟.我们引入了满足$B_ϕ\le B$的低浓度柱状缺陷。同时考虑了薄饼涡之间的电磁相互作用和约瑟夫森相互作用。纳米晶，纳米液体和均匀的液相被确定与实验一致。我们观察到的两步熔融过程，也注意到增强的结构因子之前的熔融过渡。提出的理论模型与我们的研究结果是一致的。
Direct observation of vortex liquid droplets in the iron pnictide superconductor CaKAs$_4$Fe$_4$ at $0.5T$_c$
Universidad Autónoma de Madrid（马德里自治大学）；Michigan State University（密歇根州立大学）；Ames National Laboratory, Iowa State University（爱荷华州立大学艾姆斯国家实验室）；Iowa State University（爱荷华州立大学）；Universidad de Buenos Aires（布宜诺斯艾利斯大学）
Thermally Configurable Multi-Order Polar Skyrmions in Multiferroic Oxide Superlattices
State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University（浙江大学材料科学与工程学院硅与先进半导体材料省部共建国家重点实验室）；Zhejiang Key Laboratory of Advanced Solid State Energy Storage Technology and Applications, Taizhou Institute of Zhejiang University（浙江工业大学储能技术与应用浙江省重点实验室台州研究院）；Institute of Fundamental and Transdisciplinary Research, Zhejiang University（浙江大学基础与交叉科学研究院）；School of Engineering, Hangzhou City University（杭州城市学院工学院）；College of Materials Science and Engineering, Zhejiang University of Technology（浙江工业大学材料科学与工程学院）
