Publications

2019
B. Loret, et al., “Intimate link between charge density wave, pseudogap and superconducting energy scales in cuprates”, Nature Physics, vol. 15, p. 771-775, 2019. WebsiteAbstract
The cuprate high-temperature superconductors develop spontaneous charge density wave (CDW) order below a temperature TCDW and over a wide range of hole doping (p). An outstanding challenge in the field is to understand whether this modulated phase is related to the more exhaustively studied pseudogap and superconducting phases1,2. To address this issue, it is important to extract the energy scale DCDW associated with the CDW order, and to compare it with the pseudogap DPG and with the superconducting gap DSC. However, while TCDW is well characterized from earlier work3, little is currently known about DCDW. Here, we report the extraction of DCDW for several cuprates using electronic Raman spectroscopy. We find that on approaching the parent Mott state by lowering p, DCDW increases in a manner similar to the doping dependence of DPG and DSC. This reveals that these three phases have a common microscopic origin. In addition, we find that DCDW [?] DSC over a substantial doping range, which suggests that CDW and superconducting phases are intimately related; for example, they may be intertwined or connected by an emergent symmetry1,4-9.
2018
O. Najera, Civelli, M., Dobrosavljevic, V., and Rozenberg, M. J., “Multiple crossovers and coherent states in a Mott-Peierls insulator”, PHYSICAL REVIEW B, vol. 97, p. 045108, 2018.Abstract
We consider the dimer Hubbard model within dynamical mean-field theory to study the interplay and competition between Mott and Peierls physics. We describe the various metal-insulator transition lines of the phase diagram and the breakdown of the different solutions that occur along them. We focus on the specific issue of the debated Mott-Peierls insulator crossover and describe the systematic evolution of the electronic structure across the phase diagram. We found that at low intradimer hopping, the emerging local magnetic moments can unbind above a characteristic singlet temperature T{*}. Upon increasing the interdimer hopping, subtle changes occur in the electronic structure. Notably, we find Hubbard bands of a mix character with coherent and incoherent excitations. We argue that this statemight be relevant formaterials such as VO2 and its signaturesmay be observed in spectroscopic studies, and possibly through pump-probe experiments.