标题： Sr$_3$Ru$_2$O$_7$中的多重磁性量子临界性 显示英文标题

标题： Multiple metamagnetic quantum criticality in Sr$_3$Ru$_2$O$_7$

摘要： 双层锶钌酸盐 Sr$_3$Ru$_2$O$_7$在垂直于钌酸盐平面的约 8 T 磁场下表现出显著的非费米液体行为，这之前被认为与巡游型磁相变量子临界终点（QCEP）有关。 我们关注磁 格吕内森参数$\Gamma_{\rm H}$，这是最直接的探测手段，用于表征场诱导的量子临界性。 我们确认了在 7.845(5) T 附近存在一个假定的二维 QCEP 的量子临界标度，该点被两种有序相 A 和 B 掩盖，这两种相之前通过中子散射已被识别。 此外，我们还发现了在 7.53(2) T 处存在一个 QCEP，并确定了两种不稳定性各自的量子临界区域以及它们叠加的影响。 显示英文摘要

摘要： Bilayer strontium ruthenate Sr$_3$Ru$_2$O$_7$ displays pronounced non-Fermi liquid behavior at magnetic fields around 8 T, applied perpendicular to the ruthenate planes, which previously has been associated with an itinerant metamagnetic quantum critical end point (QCEP). We focus on the magnetic Gr\"uneisen parameter $\Gamma_{\rm H}$, which is the most direct probe to characterize field-induced quantum criticality. We confirm quantum critical scaling due to a putative two-dimensional QCEP near 7.845(5) T, which is masked by two ordered phases A and B, identified previously by neutron scattering. In addition we find evidence for a QCEP at 7.53(2) T and determine the quantum critical regimes of both instabilities and the effect of their superposition.