Phase evolution of Ce-based heavy-fermion superconductors under pressure: a combined DFT+DMFT and effective-model description

In typical Ce-based heavy-fermion superconductors, superconducting (SC) phases emerge or can be tuned in proximity to the antiferromagnetic (AF) quantum critical point (QCP), but so far the explicit phase-evolution process and the coexistence of superconductivity and AF order near the QCP remain lack of understanding. Here, by combing DFT+DMFT with effective-model calculations, we provide a theoretical description for Ce-based SC compounds under pressure. Firstly, DFT+DMFT calculations for the normal states reveal that the Kondo hybridizations are significantly enhanced, while the initially localized $f$ electrons eventually become fully itinerant via a localized-itinerant crossover. In this context, we construct an effective model with tunable parameters under pressure, and show that the interplay of magnetic correlation and Kondo hybridization can drive successive transitions, from AF phase to AF+SC coexisting phase, then to paramagnetic SC phase via an AF transition which corresponds to the QCP, and finally to Kondo paramagnetic phase through a SC transition driven by localized-itinerant crossover. Our study gives a proper explanation for the pressure-induced magnetic QCP and SC transition, and for the phase-evolution process under pressure in typical Ce-based superconductors, and may also help to understand the SC states emerging around the ferromagnetic quantum transition points in uranium-based superconductors.Comment: 13 pages, 11 figure

A 0.76-pJ/Pulse 0.1-1 Gpps Microwatt IR-UWB CMOS Pulse Generator with Adaptive PSD Control Using A Limited Monocycle Precharge Technique

Document Version Author final version (often known as postprint) Link to publication from Aalborg University Citation for published version (APA)