Three-Dimensional Charge Density Wave Order in YBa2Cu3O6.67 at High Magnetic Fields
S. Gerber, H. Jang, H. Nojiri, S. Matsuzawa, H. Yasumura, D. A. Bonn, R. Liang, W. N. Hardy, Z. Islam, A. Mehta, S. Song, M. Sikorski, D. Stefanescu, Y. Feng, S… 展开作者
S. Gerber, H. Jang, H. Nojiri, S. Matsuzawa, H. Yasumura, D. A. Bonn, R. Liang, W. N. Hardy, Z. Islam, A. Mehta, S. Song, M. Sikorski, D. Stefanescu, Y. Feng, S. A. Kivelson, T. P. Devereaux, Z. -X. Shen, C. -C. Kao, W. -S. Lee, D. Zhu, J. -S. Lee
Charge density wave (CDW) correlations have recently been shown to universally exist in cuprate superconductors. However, their nature at high fields inferred from nuclear magnetic resonance is distinct from that measured by x-ray scattering at zero and low fields. Here we combine a pulsed magnet with an x-ray free electron laser to characterize the CDW in YBa2Cu3O6.67 via x-ray scattering in fields up to 28 Tesla. While the zero-field CDW order, which develops below T ~ 150 K, is essentially two-dimensional, at lower temperature and beyond 15 Tesla, another three-dimensionally ordered CDW emerges. The field-induced CDW onsets around the zero-field superconducting transition temperature, yet the incommensurate in-plane ordering vector is field-independent. This implies that the two forms of CDW and high-temperature superconductivity are intimately linked.
Magnetic field control of charge structures in the magnetically disordered phase of the multiferroic LuFe$_2$O$_4$
利用中子衍射研究了磁场对电荷有序多铁性材料LuFe $_2$ O $_4$中电荷结构的影响。一个外部磁场能够改变的大小和相关长度的电荷价序，甚至在磁秩序设置。这会影响材料的介电和铁电特性，并引起巨磁电效应。我们的研究结果表明，在LuFe $_2$ O $_4$的磁电耦合可能是由于局部自旋磁场效应，在明显的对比，在大多数其他已知的多铁性系统的情况下，体磁秩序是重要的。
