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Quasiparticle scattering spectroscopy (QPS) applied to heavy fermions utilizes a ballistic junction to probe how electrons scatter off strongly energy-dependent density of states in the bulk^[1]. Our previous QPS study on URu₂Si_2-xP_x^[2] found that a hybridization gap opens regardless of the ground state ordering as it was also observed in the no-order region, consistent with earlier reports where a hybridization gap was observed to open well above the hidden order transition temperature in URu₂Si₂^[1]. Fe substitution acts like the application of chemical pressure^[3] and the resulting phase diagram closely resembles the case of hydrostatic pressure, providing a new opportunity to probe the coexistent/competing region. We will present conductance spectra as a function of temperature and chemical substitution and discuss the correlation between hybridization process and emergent ground states.
[1] W. K. Park et al. PRL 108, 246403 (2012) [2] A. Gallagher et al. Nat. Commun. 7, 10712 (2016) [3] S. Ran et al. PNAS 113,13348(2016).