Tuning soft point-contact spectroscopy of URu$_{2}$Si$_{2}$ from hidden order to antiferromagnetic state through pressure
ORAL
Abstract
We have extended the soft point-contact spectroscopy technique under nearly hydrostatic pressure to make charge-spectroscopy measurements of URu$_{2}$Si$_{2}$ in both hidden order (HO) and large-moment antiferromagnetic (LMAF) states. In the HO state at ambient pressure, the spectroscopy shows two asymmetric peaks around the Fermi energy that emerge below the hidden order temperature T$_{HO}\sim $ 17.5 K. In the LMAF state at higher pressures, the spectra are remarkably similar to those in the HO state, indicating a similar Fermi surface gapping in the HO and LMAF states. The energy scale of this gap is, within experimental uncertainty, consistent with that of the incommensurate spin resonance at Q$_{1}$= (1$\pm $0.4, 0, 0), which also is present in both HO and LMAF states. Our results provide a new clue to unraveling the puzzling HO state.
*Work at Los Alamos was performed under the auspices of the U. S. Department of Energy, Division of Materials Science and Engineering and supported in part by the Los Alamos LDRD program.
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