Pseudogap metal induced by long-range Coulomb interactions

A quantum theory of the nearly frozen charge glass

“…It can be seen as a practical implementation of early ideas of Andreev and Kosevich [9] and Efros [10], who hypothesized a clear separation of time-scales between fast individual and slow collective motions, the latter being severely slowed down by the existence of many-body interactions at all distances. This "two fluid" behavior of the frustrated Coulomb system has been recently confirmed by a fully quantum study of long-range interacting electrons on the triangular lattice [22].…”

“…To do so, we perform a strong coupling perturbation expansion, treating the kinetic term in Eq. ( 1) to lowest order in t p /V , following a methodology that was successfully applied to study the quantum melting of the charge ordered state in the presence of long-range Coulomb interactions both in one [17,18] and two space dimensions [21,22]. This method was shown to correctly capture the proliferation of defects involved in the quantum melting mechanism at T = 0, providing results in quantitative agreement with full exact diagonalization.…”

Displaced Drude peak and bad metal from the interaction with slow fluctuations.

“…As our results have demonstrated, a sufficient requirement for the emergence of a localization-induced DDP is the presence of slowly fluctuating degrees of freedom interacting with the electronic carriers. This condition is likely to be met in a variety of physical situations, as microscopic candidates are ubiquitous in complex materials -including soft lattice vibrations [5], critical modes in proximity of phase transitions [11], fluctuating magnetic moments [37], or collective charge fluctuations [33,38,39]. Regarding the latter, while charge fluctuations induced by the long-range Coulomb interactions between electrons may provide the slow bosonic modes enabling the appearance of a DDP [10,38,39], while short range correlations alone do not seem to sustain a DDP feature in the optical absorption [7][8][9].…”

“…This condition is likely to be met in a variety of physical situations, as microscopic candidates are ubiquitous in complex materials -including soft lattice vibrations [5], critical modes in proximity of phase transitions [11], fluctuating magnetic moments [37], or collective charge fluctuations [33,38,39]. Regarding the latter, while charge fluctuations induced by the long-range Coulomb interactions between electrons may provide the slow bosonic modes enabling the appearance of a DDP [10,38,39], while short range correlations alone do not seem to sustain a DDP feature in the optical absorption [7][8][9]. On general grounds, local repulsive interactions are expected to suppress charge fluctuations and other forms of self-generated randomness, in particular at integer fillings.…”

Rise and Fall of Landau's Quasiparticles While Approaching the Mott Transition

“…Finally, we argue that long-range Coulomb interactions, that are usually neglected in theoretical treatments of correlated electron systems, could actually play a key role both in the present compounds as well as in other bad metals where DDPs have been reported 46 . The ability of non-local interactions in providing an effective disordered medium for lattice electrons has been recognized recently [49][50][51][52] , with direct consequences on bad-metallic behavior 53 . The additional scattering channel associated with long-range potentials could well be amplified at the approach of the Mott transition, due to both reduced screening and collective slowing down of the resulting randomness, possibly causing DDP behavior as observed here.…”