Emergence of heavy quasiparticles and their superconductivity

In examining the properties of correlated electronic systems, our group has directly visualized the process whereby interaction between electrons can give rise to emergent heavy quasiparticles. While there has been indirect evidence for heavy quasiparticles in a strongly interacting system, our group’s study was the first to probe the energy-momentum structure of these electronic states to directly prove their heavy mass characteristics as well as demonstrating their composite nature.[P. Aynajian et al, Nature 486 (2012), P. Aynajian et al Journal of the Physical Society of Japan 83 (2014)]

We have also studied how these heavy electrons transform into a superconducting state with the lowering of temperature and have provided direct evidence for the d-wave symmetry of their superconducting order parameter. [B. Zhou et al, Nature Physics 9 (2013)]  In other studies of heavy fermion systems, we have explored the properties of some of these novel materials developing hidden order [P. Aynajian et al, PNAS 107 (2010)] as well as the role of material dimensionality in the emergence of heavy quasi-particles [A. Gyenis et al, Nature Communications 9 (2018)].
 

Quasiparticle interference reveals hybridization gap and the heavy bands.

Quasiparticle interference reveals hybridization gap and the heavy bands.