Geometric frustration produces Bose metal as a failed insulator and probing it with electrons produces generic non-Fermi liquid scattering and pseudogap phenomenaphysics

Two of the most prominent phases of bosonic matter are the superfluid with perfect flow and the insulator with no flow. A now decades-old mystery unexpectedly arose when experimental observations indicated that bosons could organize into the formation of an entirely different intervening third phase: the Bose metal with dissipative flow. We recently proposed a universal homogeneous theory for a Bose metal in which geometric frustration confines the essential quantum coherence to a lower dimension resulting in a gapless insulator characterized by dissipative flow that vanishes in the low-energy limit. Even more recently, we have demonstrated that non-Fermi liquid behavior and pseudogap formation are inevitable consequences when fermions couple to our Bose metal at mean field level due to its unconventional lower-dimensional coherence. Not only do we find both exotic phenomena, but also a host of other features that have been observed e.g. in the cuprates including nodal anti-nodal dichotomy and pseudogap asymmetry (symmetry) in momentum (real) space. Obtaining these exotic and heretofore mysterious phenomena offers a simple, universal, and therefore widely applicable explanation for their ubiquitous empirical appearance.