Quantum oscillations and quasiparticle properties of thin film Sr2RuO4
Quantum oscillations and quasiparticle properties of thin film Sr2RuO4
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DOI：
10.1103/physrevb.104.045152
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发表时间：
2021-03
影响因子：
3.7
通讯作者：
Yawen Fang;H. Nair;L. Miao;B. Goodge;N. Schreiber;J. Ruf;L. Kourkoutis;K. Shen;D. Schlom;B. Ramshaw
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文献类型：
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作者：
Yawen Fang;H. Nair;L. Miao;B. Goodge;N. Schreiber;J. Ruf;L. Kourkoutis;K. Shen;D. Schlom;B. Ramshaw
测量了生长在（LaAlO 3）0.29-（SrAl 1/2 Ta 1/2 O3）0.71（LSAT）衬底上的Sr 2 RuO 4薄膜的舒布尼科夫-德哈斯效应。我们检测所有三个已知的费米面，并提取费米面体积，回旋有效质量和量子寿命。我们发现，电子结构是几乎相同的单晶Sr $_2$RuO$_4 $，和准粒子寿命是一致的Tc的无杂质，单晶Sr $_2$RuO$_4 $。不像单晶Sr$_2$RuO$_4$，其中量子和运输寿命大致相等，我们发现，运输寿命是1.3\pm0.1 $倍以上的量子寿命。这表明，扩展（而不是点）缺陷可能是这些薄膜中的准粒子散射的主要来源。为了验证这一想法，我们进行横截面STEM和发现，异相边界延伸的整个厚度的薄膜发生的密度是一致的量子平均free path. The长准粒子寿命使这些薄膜的理想研究的非常规超导状态Sr $_2$RuO$_4 $通过制造设备-如平面隧道结和SQUID。
We measure the Shubnikov-de Haas effect in thin-film Sr$_2$RuO$_4$ grown on an (LaAlO$_3$)$_{0.29}$-(SrAl$_{1/2}$Ta$_{1/2}$O$_3$)$_{0.71}$ (LSAT) substrate. We detect all three known Fermi surfaces and extract the Fermi surface volumes, cyclotron effective masses, and quantum lifetimes. We show that the electronic structure is nearly identical to that of single-crystal Sr$_2$RuO$_4$, and that the quasiparticle lifetime is consistent with the Tc of comparably clean, single-crystal Sr$_2$RuO$_4$. Unlike single-crystal Sr$_2$RuO$_4$, where the quantum and transport lifetimes are roughly equal, we find that the transport lifetime is $1.3\pm0.1$ times longer than the quantum lifetime. This suggests that extended (rather than point) defects may be the dominant source of quasiparticle scattering in these films. To test this idea, we perform cross-sectional STEM and find that out-of-phase boundaries extending the entire thickness of the film occur with a density that is consistent with the quantum mean free path. The long quasiparticle lifetimes make these films ideal for studying the unconventional superconducting state in Sr$_2$RuO$_4$ through the fabrication of devices -- such as planar tunnel junctions and SQUIDs.