TY - GEN AB - The exact nature of the unconventional superconductivity in Sr<sub>2</sub>RuO<sub>4</sub> remains a mystery. At the phenomenological level, no superconducting order parameter proposed thus far seems able to coherently account for all essential experimental signatures. Among the latter is the prominent polar Kerr effect, which implies a nonzero ac anomalous Hall conductivity. Assuming the Kerr effect is intrinsic, it can be accounted for by a bulk chiral Cooper pairing with nonzero orbital angular momentum, such as p + ip or d + id, which, however, has difficulties in being reconciled with other experimental results. Given the situation, in this paper we propose alternative possibilities with complex mixtures of distinct helical p-wave order parameters, namely A<sub>1u</sub> + i A <sub>2u</sub> and B<sub>1u</sub> + iB<sub>2u</sub> in group theory nomenclature. These states essentially consist of two copies of chiral p-wave pairings with opposite chirality and different pairing amplitudes, and therefore they support intrinsic Hall and Kerr effects. We further show that these states exhibit salient features that may explain several other key observations in this material, including the absence of spontaneous edge current, a substantial Knight shift drop, and possibly signatures in uniaxial strain and ultrasound measurements. AD - Shenzhen Institute for Quantum Science and Engineering AD - University of Chicago AU - Huang, Wen AU - Wang, Zhiqiang DA - 2021-10-07 ID - 11685 JF - Physical Review Research L1 - https://knowledge.uchicago.edu/record/11685/files/PhysRevResearch.3.L042002.pdf L1 - https://knowledge.uchicago.edu/record/11685/files/supplementary.pdf L2 - https://knowledge.uchicago.edu/record/11685/files/PhysRevResearch.3.L042002.pdf L2 - https://knowledge.uchicago.edu/record/11685/files/supplementary.pdf L4 - https://knowledge.uchicago.edu/record/11685/files/PhysRevResearch.3.L042002.pdf L4 - https://knowledge.uchicago.edu/record/11685/files/supplementary.pdf LA - eng LK - https://knowledge.uchicago.edu/record/11685/files/PhysRevResearch.3.L042002.pdf LK - https://knowledge.uchicago.edu/record/11685/files/supplementary.pdf N2 - The exact nature of the unconventional superconductivity in Sr<sub>2</sub>RuO<sub>4</sub> remains a mystery. At the phenomenological level, no superconducting order parameter proposed thus far seems able to coherently account for all essential experimental signatures. Among the latter is the prominent polar Kerr effect, which implies a nonzero ac anomalous Hall conductivity. Assuming the Kerr effect is intrinsic, it can be accounted for by a bulk chiral Cooper pairing with nonzero orbital angular momentum, such as p + ip or d + id, which, however, has difficulties in being reconciled with other experimental results. Given the situation, in this paper we propose alternative possibilities with complex mixtures of distinct helical p-wave order parameters, namely A<sub>1u</sub> + i A <sub>2u</sub> and B<sub>1u</sub> + iB<sub>2u</sub> in group theory nomenclature. These states essentially consist of two copies of chiral p-wave pairings with opposite chirality and different pairing amplitudes, and therefore they support intrinsic Hall and Kerr effects. We further show that these states exhibit salient features that may explain several other key observations in this material, including the absence of spontaneous edge current, a substantial Knight shift drop, and possibly signatures in uniaxial strain and ultrasound measurements. PY - 2021-10-07 T1 - Possibility of mixed helical p-wave pairings in Sr<sub>2</sub>RuO<sub>4</sub> TI - Possibility of mixed helical p-wave pairings in Sr<sub>2</sub>RuO<sub>4</sub> UR - https://knowledge.uchicago.edu/record/11685/files/PhysRevResearch.3.L042002.pdf UR - https://knowledge.uchicago.edu/record/11685/files/supplementary.pdf Y1 - 2021-10-07 ER -