Study of the hidden-order of URu2Si2 by point contact tunnel junctions

TL;DR

This study investigates the electronic properties of URu2Si2, focusing on its hidden order and superconductivity, using tunneling and point contact spectroscopies to reveal the influence of Fano and Kondo resonances and Fermi surface nesting.

Contribution

It provides new insights into the electronic characteristics and Fermi surface behavior of URu2Si2 related to its hidden order and superconducting states using spectroscopic techniques.

Findings

Energy gap determined in the superconducting state shows resonance influences.

Spectra at hidden order temperatures reveal Fano and Kondo resonance effects.

Fermi surface nesting varies with crystallographic direction.

Abstract

URu2Si2 presents superconductivity at temperatures below 1.5 K, and a hidden order (HO) at about 17.5 K, both electronic phenomena are in uenced by Fano and Kondo resonances. At 17.5 K the HO was related in the past to a Peierls distortion that produces an energy gap deformed by the resonances. This order has been studied by more than 20 years, still without a clear understanding. In this work we studied the electronic characteristics of URu2Si2 in a single crystal, with tunneling and metallic point contact spectroscopies. In the superconducting state, we determined the energy gap, which shows the in uence of the Fano and Kondo resonances. At temperatures where HO is observed, the tunnel junctions spectra show the in uence of the two resonances. Tunnel junctions characteristics show that the Fermi surface nesting depends on the crystallographic direction.