Fermi-Bose crossover using engineered disorder potential

Abstract

We present the first instance of a disorder tuned Fermi-Bose crossover that could be realized in superconducting systems. More specifically, harnessing a non perturbative numerical technique we analyze the ground state behavior of a two-dimensional attractive Hubbard model subjected to spin selective disorder potential. In particular, using spectroscopic properties we provide unambiguous evidence of the change in the Fermi surface topology as a function of the disorder, establishing incontrovertibly a Fermi-Bose crossover. Interplay of strong correlations and strong disorder brings out the spin selectivity in the properties of this system giving rise to spin selective "Bose metal/insulator" phase. We propose an experimental set-up where such disorder tuned Fermi-Bose crossover could be observed in two-dimensional electron gas formed at oxide interface. Finally, we speculate on the possible implication of such spin-selective disorder on unraveling signatures of Bose-Fermi cross-over on doped iron chalcogenide superconductors.