| Автор | Robert Haslinger |
| Автор | Robert Joynt |
| Дата выпуска | 2000-09-18 |
| dc.description | Josephson tunnelling between YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> and Pb with the current flowing along the c-axis of the YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> is presumed to arise from an s-wave component of the superconductivity in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>. Experiments on multi-twin samples are not entirely consistent with this hypothesis. The sign changes of the s-wave order parameter across the N<sub>T</sub> twin boundaries should give cancellations, resulting in a small ((N<sub>T</sub>)<sup>1/2</sup>) tunnelling current. The actual current is larger than this. We present a theory of this unexpectedly large current based upon a surface effect: disorder-induced suppression of the d-wave component at the (001) surface leads to s-wave coherence across the twin boundaries and a non-random tunnelling current. We solve the case of an ordered array of d + s and d-s twins, and estimate that the twin size at which s-wave surface coherence occurs is consistent with typical sizes observed in experiments. In this picture, there is a phase difference of π/2 between different surfaces of the material. We propose a corner-junction experiment to test this picture. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | c-axis Josephson tunnelling in twinned YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> (YBCO) crystals |
| Тип | paper |
| DOI | 10.1088/0953-8984/12/37/315 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 12 |
| Первая страница | 8179 |
| Последняя страница | 8190 |
| Выпуск | 37 |
