I. Physikalisches Institut, Georg-August-Universität Göttingen, D-37077 Göttingen, Germany.
Phys Rev Lett. 2011 Jul 8;107(2):026404. doi: 10.1103/PhysRevLett.107.026404. Epub 2011 Jul 6.
The electronic nematic phase of Sr₃Ru₂O₇ is investigated by high-resolution in-plane thermal expansion measurements in magnetic fields close to 8 T applied at various angles Θ off the c axis. At Θ < 10° we observe a very small (10⁻⁷) lattice distortion which breaks the fourfold in-plane symmetry, resulting in nematic domains with interchanged a and b axis. At Θ ≳ 10° the domains are almost fully aligned and thermal expansion indicates an area-preserving lattice distortion of order 2 × 10⁻⁶ which is likely related to orbital ordering. Since the system is located in the immediate vicinity of a metamagnetic quantum critical end point, the results represent the first observation of a structural relaxation driven by quantum criticality.
通过在磁场中沿 c 轴以不同角度 Θ（远离 c 轴）施加高分辨率的面内热膨胀测量，研究了 Sr₃Ru₂O₇ 的电子向列相。在 Θ < 10°时，我们观察到非常小的（10⁻⁷）晶格畸变，打破了四重面内对称，导致 a 和 b 轴相互交换的向列畴。在 Θ ≳ 10°时，畴几乎完全对齐，热膨胀表明存在约 2 × 10⁻⁶的保面积晶格畸变，这可能与轨道有序有关。由于该系统位于顺磁量子临界点的附近，因此结果代表了首次观察到由量子临界点驱动的结构弛豫。
