Detailed optical spectroscopy of the hybridization gap and the hidden order transitionin high quality URu2Si2 single crystals

Article Article scientifique Article Detailed optical spectroscopy of the hybridization gap and the hidden order transitionin high quality URu2Si2 single crystals eng 2016 author Bachar Nimrod 830670 author Stricker Damien 631826 author Muleady Sean Robert 840130 author Wang Kai 828933 author Mydosh J. A. author Huang Y. K. author Van Der Marel Dirk 0000-0001-5266-9847 135104 10.1103/PhysRevB.94.235101 1098-0121 https://link.aps.org/doi/10.1103/PhysRevB.94.235101 We present a detailed temperature and frequency dependence of the optical conductivity measured on clean high quality single crystals of URu2Si2 of ac- and ab-plane surfaces. Our data demonstrate the itinerant character of the narrow 5f bands, becoming progressively coherent as temperature is lowered below a cross-over temperature T∗∼75K. T∗is higher than in previous reports as a result of a different sample preparation, which minimizes residual strain. We furthermore present the density-response (energy-loss) function of this compound, and determine the energies of the heavy fermion plasmons witha-andc-axis polarization. Our observation of a suppression of optical conductivity below 50 meV both alongaandc-axis, along with a heavy fermion plasmon at 18 meV, points toward the emergence of a band of coherent charge carriers crossing the Fermi energy and the emergence of a hybridization gap on part of the Fermi surface. The evolution towards coherent itinerant states is accelerated below the hidden order temperature THO= 17.5K. In the hidden order phase the low frequency optical conductivity shows a single gap at∼6.5 meV, which closes at THO. Dewey 500.2 33 Département de physique de la matière quantique 131 false 785 Groupe Van der Marel Physical Review. B, Condensed Matter 94 235101 f2446d6b-9ad3-4fc7-8c02-032109317658 Article (Submitted version) Public bachar2016.pdf 4291130 application/pdf openAccess Faculté des sciences / Section de physique / Département de physique de la matière quantique

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Detailed optical spectroscopy of the hybridization gap and the hidden order transitionin high quality URu₂Si₂ single crystals	Physical Review. B, Condensed Matter			2016	310	102

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Muleady, Sean Robert