Constrain relations for superfluid weight and pairings in a chiral flat band superconductor

Within ten years, flat band (FB) superconductivity has gained a huge interest for its remarkable features and connection to quantum geometry. We investigate the superconductivity in a FB system whose orbitals are inequivalent and in which the gap and the quantum metric are tunable. The key feature of the present theoretical study is to show a unique and simple constrain relation that pairings obey. Furthermore, pairings and superfluid weight in partially filled FB are shown to be controlled by those of the half-filled lattice. We argue that the geometry of the lattice or the complexity of the hopping terms have no impact on the features revealed in this work as far as the system is bipartite.Comment: 9 pages, 6 figure

Universal relations in flat band superconducting bipartite lattices

Unconventional flat band (FB) superconductivity, as observed in van der Waals heterostructures, could open promising avenues towards high-T$_c$ materials. Indeed, in FBs, pairings and superfluid weight scale linearly with the interaction parameter, such an unusual behaviour justifies strategies to promote FB engineering. Bipartite lattices (BLs) which naturally host FBs could be particularly interesting candidates. By revealing a hidden symmetry of the quasi-particle eigenstates, we demonstrate that pairings and superfluid weight obey universal relations in BLs. Remarkably, these general properties are insensitive to disorder as long as the bipartite character is protected.Comment: 5 figure

Tests on riveted joints in sheet duralumin

In making tension tests, the slippage of the joints was noted at three points across each joint. In addition, stress strain curves were obtained for plain tension specimens, and a chemical analysis was made of the sheet

Flat-band superconductivity in a system with a tunable quantum metric: The stub lattice

International audienc

Constrain relations for superfluid weight and pairings in a chiral flat band superconductor

Abstract Within ten years, flat band (FB) superconductivity has gained a huge interest for its remarkable features and connection to quantum geometry. We investigate the superconductivity in a FB system whose orbitals are inequivalent and in which the gap and the quantum metric are tunable. 
The key feature of the present theoretical study is to show a unique and simple constrain relation that pairings obey. 
Furthermore, pairings and superfluid weight in partially filled FB are shown to be controlled by those of the half-filled lattice.
We argue that the geometry of the lattice or the complexity of the hopping terms have no impact on the features revealed in this work as far as the system is bipartite

Universal relations in flat band superconducting bipartite lattices

5 figuresUnconventional flat band (FB) superconductivity, as observed in van der Waals heterostructures, could open promising avenues towards high-T$_c$ materials. Indeed, in FBs, pairings and superfluid weight scale linearly with the interaction parameter, such an unusual behaviour justifies strategies to promote FB engineering. Bipartite lattices (BLs) which naturally host FBs could be particularly interesting candidates. By revealing a hidden symmetry of the quasi-particle eigenstates, we demonstrate that pairings and superfluid weight obey universal relations in BLs. Remarkably, these general properties are insensitive to disorder as long as the bipartite character is protected

NACA Technical Notes

In making tension tests, the slippage of the joints was noted at three points across each joint. In addition, stress strain curves were obtained for plain tension specimens, and a chemical analysis was made of the sheet

Synthesis of N-glycosides. An alternative approach based on diastereoselective base coupling and SN2 cyclization

Chemical equation presented Acyclic diastereoselection is achieved for the formation of thioaminyl acetals. The highly intramolecular stereocontrolled SN2 displacement of the thioaminyls allows for the formation of cyclic nucleoside derivatives. This versatile approach may provide easy access to a large variety of N-glycosides