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TT: Fachverband Tiefe Temperaturen
TT 23: CE: Quantum-Critical Phenomena 2
TT 23.2: Talk
Tuesday, March 15, 2011, 10:45–11:00, HSZ 105
Uniform lattice distortion in the nematic phase of Sr3Ru2O7 — •Christian Stingl and Philipp Gegenwart — I. Physikalisches Institut, Georg-August-Universität Göttingen
In the itinerant metamagnet Sr3Ru2O7, a first order metamagnetic transition is suppressed to a quantum critical end point (QCEP) at T=0 by applying a magnetic field µ0 Hc = 7.85 T along the c-axis. Quantum critical behaviour is observed in thermal expansion and can be explained in terms of 2d ferromagnetic fluctuations [1].
Below 1 K, a new phase with a strongly enhanced residual resistivity forms in the vicinity of the QCEP. When H has a small in-plane component, the resistivity becomes anisotropic, which is discussed in terms of formation of an electronic nematic fluid organized into domains [2].
We present in-plane thermal expansion and magnetostriction measurements obtained by high-resolution capacitive dilatometry. Our findings suggest that inside the nematic phase, the four-fold symmetry is broken by a uniform lattice distortion with Δ L/L of the order of 10−6. The results are discussed in the context of a recent model [3] for domain formation via partial orbital ordering.
This work is in collaboration with F. Weickert, R. Küchler,
R.S. Perry and Y. Maeno and supported by the DFG through SFB602.
P. Gegenwart et al., PRL 96, 136402 (2006)
R.A. Borzi et al., Science 315, 214-217 (2007)
W.-C. Lee and C. Wu, arXiv:1008.2486