Topological disorder triggered by interaction-induced flattening of electron spectra in solids

Effect of superconductivity on the shape of flat bands

“…( 11) describes the state with FC characterized by the superconducting order parameter κ 0 (p) = n 0 (p)(1 − n 0 (p)) where the functions n 0 (p) are solutions of Eq. (11). It is instructive to construct F + (p, ω) and G(p, ω) when g is finite but small so that the functions v 2 (p) and κ(p) can be approximated by the solutions of Eq.…”

“…Flat bands in Fermi systems with strong interaction were predicted about thirty years ago [4], and the properties of such systems are predicted and described in details, see e.g. [2,[5][6][7][8][9][10][11][12][13]. Topological approach turns out to be a powerful method to gain information about a wide class of physical systems.…”

“…The concept of FCQPT, forming the recent experimentally discovered flat bands, originated long ago [4]. At first, this idea appeared as a mathematical curiosity, but now the fermion condensation theory, based on FCQPT, represents an expanding field with numerous applications [2,[5][6][7][8][9][10][11][12][13]. Flat bands have been discovered experimentally in magic angle twisted bilayer graphene (MATBG).…”

“…This flat band becomes highly susceptible to reconstruction induced by external and internal factors such as magnetic field B, temperature T , including the setting in of phase transitions like antiferromagnetic, SC, etc, see e.g. [2,5,[9][10][11]. In case of the flat band, the gap ∆ depends linearly on the pairing interaction constant g, ∆ ∝ g, see e.g.…”

Magnetic-field-driven redistribution between extended and localized electronic states in high-mobility Si MOSFETs at low temperatures

“…at r s ≫ 1 [4]. Different approaches to this problem gave birth to a plethora of theoretical suggestions [5][6][7][8][9] for the ground states of strongly interacting electron systems.…”