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Researchers
Introduction
The quantum mechanical problem of correlated electron in solids is one of the great, unsolved mysteries faced by modern physics. Transition metal oxides provide an ideal environment to study this problem.
We investigate the bilayer ruthenate metal Sr3Ru2O7 (Sr327). ). Unlike its single-layer sister compound Sr2RuO4, Sr327 is not known to be superconducting. However, it exhibits very unusual magnetic properties. At higher temperatures, a metagnetic transition occurs. Following the transition line to lower temperatures, at the putative quantum critical point, a new, one-dimensional ("nematic") electronic phase can be found (R. A. Borzi et al., Science 315, 214 (January 12, 2007, 2007).
Together with our collaborators in St. Andrews, we hope to shed some light on the physics of the nematicity and the metamagnetism in this unusual compound.
Instrument - Subkelvin 9-Tesla Spectroscopic Imaging STM (SI-STM):??
This system consists of a home-built 250mK 3He refrigerator with ultra low vibration 4He-pot surrounded by a persistent American Magnetics magnet. It is suspended in a very low boilrate dewar from a massive low vibration cryostat. The cryostat is housed inside an acoustic shield room (shown left), itself supported on a 25 ton inertial black on vibration isolators. Again, this assembly is installed in an underground acoustic/vibration isolation vault.? The pump set is remote and highly vibration isolated and the control room is remote. The STM head is at the center of the magnet suspended below the refrigerator. We use this system to study Bi2Sr2CaCu2O8+¥ä, Bi2Sr2Ca2Cu3O10+¥ä, YBa2Cu3O6+¥ä, Th2Ba2CuO6+¥ä, and Pr2-xCexCuO4.?Sample exchange to 4K takes ~4 hours and to 250mK ~8 hours.
Results
Collaborators
- Correlated Electron Systems Group
- ARPES Group, University of St. Andrews
- Los Alamos National Laboratory
- Naval Research Laboratory