Previous work on Sr2RuO4 has shown that the superconducting state is unconventional withan order parameter symmetry of px ipy. Measurements using Josephson Interferometryhave shown evidence for chiral order parameter domains on the order of 1 m in size. Tofurther search for signatures of these domains we have fabricated Josephson junctions onclean Sr2RuO4 single crystals (Tc=1.5 K) ranging from 500 nm to 4 m wide. Using anapplied magnetic eld, we modulated the critical current of the junctions to make phasesensitivemeasurements of the order parameter of the p-wave superconductor. We observedcritical current characteristics consistent with single and multiple domains being presentin the junctions. We also observed hysteresis e ects in the junctions similar to previousexperimental and theoretical work. We explored eld cooling e ects in the junctions thatshowed possible domain wall movement along the face of the junction. We also observedswitches in the critical current that are not described currently by known theory and could bean indication of vertically oriented domains. We found that our smallest (500 nm) junctionsconsistently showed characteristics consistent with single domain junctions and that ourresults are consistent with 1 u m domains.
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机译：先前对Sr2RuO4的研究表明，超导状态是非常规的，具有阶参数对称性px ipy。使用约瑟夫森干涉测量法的测量结果表明，手性顺序参数域的大小约为1 m。为了进一步寻找这些域的特征，我们在500nm至4m宽的纯净Sr2RuO4单晶（Tc = 1.5 K）上制造了约瑟夫森结。使用施加的磁场，我们调制了结的临界电流，以对p波超导体的阶跃参数进行相敏测量。我们观察到临界电流特性与结中存在的单个和多个域一致。我们还观察到结点处的磁滞效应，类似于先前的实验和理论工作。我们研究了结点处的场冷却效应，这些结果表明畴壁可能沿结点表面运动。我们还观察到临界电流中的开关，目前尚无法通过已知理论进行描述，并且可以指示垂直方向的域。我们发现我们最小的（500 nm）结点一致地显示出与单畴结点一致的特征，并且我们的结果与1 u m畴相一致。
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