Theory of Surface Effects and A・B Transition in Superfluid ^3He

超流体中的表面效应和A・B转变理论^3He

• 批准号: 10203209
• 负责人: NAGAI Katsuhiko
• 金额: $ 3.46万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10203209/
• 关键词: Superfluid He-3; Anisotropic BCS State; Surface Effect; Quasi-classical Green's function; Superfluid Density; Size Effect; 超流動^3He; 準古典的グリーン関数法; 薄膜; 表面散乱; ABM状態; BW状態; 第3音波; p-wave pairing; 相転移; 異方的超伝導

Superfluid He-3 is in a typical anisotropic BCS state which is known to be affected very much by the surface effect. To study this problem, we developed a quasi-classical Green's function method that can treat surface scattering, from specular scattering to diffusive scattering, in a unified way. We applied the method to superfluid He-3 film and discussed the A-B transition, the superfluid density, spin dynamics.We found how the A-B phase transition temperature depends on the film width as well as on the surface roughness. Our result is consistent with previous theory based on the Ginzburg-Landau approximation. The B phase is more stable when the surface is more rough. This does not agree with an experimental result by Osaka City University Group.We calculated the superfiuid density in film. We find a good agreement with the third sound experiment when the film is thin. We find superfluid mass flow changes across the film that reflects the surface effects on the p-wave order parameter.We calculated the NMR frequency shift in the B-phase and showed that finite positive shift should be found in the cw transverse NMR experiment.In summary we found that superfluid He-3 shows considerably different properties than the bulk system, reflecting the surface effects.

超流体He-3处于典型的各向异性BCS状态，已知该状态受表面效应的影响很大。为了研究这个问题，我们开发了一种准经典格林函数方法，可以以统一的方式处理从镜面散射到扩散散射的表面散射。我们将该方法应用于超流 He-3 薄膜，并讨论了 A-B 相变、超流体密度、自旋动力学。我们发现 A-B 相变温度如何取决于薄膜宽度以及表面粗糙度。我们的结果与之前基于 Ginzburg-Landau 近似的理论一致。表面越粗糙，B相越稳定。这与大阪市立大学集团的实验结果不符。我们计算了薄膜中的超流体密度。当薄膜很薄时，我们发现与第三个声音实验非常吻合。我们发现整个薄膜的超流体质量流量变化反映了 p 波阶参数的表面效应。我们计算了 B 相中的 NMR 频移，并表明在连续波横向 NMR 实验中应该发现有限的正频移。总结 我们发现超流体 He-3 显示出与本体系统显着不同的特性，反映了表面效应。

项目成果

S. Higashitani and K. Nagai: "Electromagnetic Properties of k_3+iky Superconductor Effect of Order Parameter Collective Mode"Phys. Rev. B. 62. 3042-3045 (2000)

S. Higashitani 和 K. Nagai：“k_3 iky 超导有序参数集体模式效应的电磁特性”Phys。

S,Higashitani: "Impurity Scattering Effect on Superfluidity of ^3He in Aerogel" J,Low Temp.Phys.114・1/2. 161-172 (1999)

S，Higashitani：“气凝胶中^3He超流性的杂质散射效应”J，Low Temp.Phys.114・1/2（1999）。

J.Hara, M.Ashida, S.Higashitani, K.Nagai: "Effect of Finite Reflection at the interface on diamagnetic response of normal-superconducting double-layers"J.Phys.Soc.Jpn.. 69. 3493-3496 (2000)

J.Hara、M.Ashida、S.Higashitani、K.Nagai：“界面有限反射对正常超导双层抗磁响应的影响”J.Phys.Soc.Jpn.. 69. 3493-3496（

Y.Nagato, K.Nagai: "A-B Transion of Superfluid ^3He in a Slab"Physica B(Proceedings of LT22). (in print). (2000)

Y.Nagato、K.Nagai：“超流体的 A-B 转变 ^3He in a Slab”Physica B（LT22 论文集）。

Y.Nagato,K.Nagai: "A-B Transition of Superfluid ^3He in a Slab with Rough Surfaces"Physica B. 284-288. 269-270 (2000)

Y.Nagato、K.Nagai：“粗糙表面板中超流体 ^3He 的 A-B 转变”Physica B. 284-288。