Novel properties of clean Sr3Ru2O7 near a metamagnetic quantum critical point

PERRY, R. S.; KITAGAWA, K.; A. GRIGERA, S.; RODOLFO ALBERTO BORZI; P. MACKENZIE, A.; ISHIDA, K.; MAENO, Y.

Physical Review Letters

Año: 2004 vol. 92 p. 1 - 1

0031-9007

 We present measurements on ultraclean single crystals of the bilayered ruthenate metal Sr3 Ru2 O7 ,which has a magnetic-field-tuned quantum critical point. Quantum oscillations of differing frequenciescan be seen in the resistivity both below and above its metamagnetic transition. This frequency shiftcorresponds to a small change in the Fermi surface volume that is qualitatively consistent with the smallmoment change in the magnetization across the metamagnetic transition. Very near the metamagneticfield, unusual behavior is seen. There is a strong enhancement of the resistivity in a narrow field window,with a minimum in the resistivity as a function of temperature below 1 K that becomes morepronounced as the disorder level decreases. The region of anomalous behavior is bounded at lowtemperatures by two first-order phase transitions. The implications of the results are discussed.