Quasiparticle Relaxation Across a Spin Gap in the Itinerant Antiferromagnet UNiGa5

Abstract

Ultrafast time-resolved photoinduced reflectivity is measured for the itinerant antiferromagnet UNiGa${}_5$ ($T_N\approx$85 K) from room temperature to 10 K. The relaxation time $\tau$ shows a sharp increase at $T_N$ consistent with the opening of a spin gap. In addition, the temperature dependence of $\tau$ below $T_N$ is consistent with the opening of a spin gap leading to a quasiparticle recombination bottleneck as revealed by the Rothwarf-Taylor model. This contrasts with canonical heavy fermions such as CeCoIn${}_5$ where the recombination bottleneck arises from the hybridization gap.

5 pages, 5 figures

References in corpus (1)

• Ultrafast quasiparticle relaxation dynamics in normal metals and heavy fermion materials

Cited by in corpus (3)

• Electrodynamics of Correlated Electron Materials
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