On a large class of lattices (such as the sawtooth chain, the kagome and the pyrochlore
lattices), the quantum Heisenberg and the repulsive Hubbard models may host a completely …

During the past two decades, density-functional (DF) theory has evolved from niche
applications for simple solid-state materials to become a workhorse method for studying a …

One novel arena for designing superconductors with high TC is the flat band system. A basic
idea is that flat bands, arising from quantum mechanical interference, give unique …

The discovery of magnetism by the ancient Greeks was enabled by the natural occurrence of
lodestone–a magnetized version of the mineral magnetite. Nowadays, natural minerals …

To explore whether a flat-band system can accommodate superconductivity, we consider
repulsively interacting fermions on the diamond chain, a simplest possible quasi-one …

Herbertsmithite [ZnCu 3 (OH) 6 Cl 2] is often discussed as the best realization of the highly
frustrated antiferromagnetic kagome lattice known so far. We employ density functional …

Most quantum entanglement investigations are focused on two qubits or some finite (small)
chain structure, since the infinite chain structure is a considerably cumbersome task …

We address the long-standing problem of the microscopic origin of the richly diverse
phenomena in the chromium breathing pyrochlore material family. Combining electronic …

We construct a microscopic spin-exchange Hamiltonian for the quasi–one-dimensional (1D)
Ising magnet C o N b 2 O 6 that captures detailed and hitherto-unexplained aspects of its …

The Heisenberg quantum antiferromagnet on the maple leaf lattice has been shown to
feature highly exotic phases, and therefore material realizations are intensely sought after …