The Hubbard model provides a playground for investigating the physics of a wide range of strongly correlated systems. An important feature of these systems is the Mott insulator phase, where at half-filling, an electron gets localised on a single lattice site. In this work, we extend the idea to cluster Mott insulators-- where an electron is now localised on clusters of sites. To that end, we...
We combine density functional theory (DFT) with special quasirandom structures (QRS) and occupation control matrix (OCM) methods to investigate the magnetic ordering and pressure effects on manganese sulfide polymorphs. MnS is usually found in paramagnetic (PM) rock-salt (RS) structure under ambient conditions, but it becomes antiferromagnetic (AFM) as temperature decreases at constant...
Condensed matter systems can possess striking parallels with gauge theories that arise in the context of high-energy physics, exemplified by the Anderson-Higgs transition in superconductors [1], and emergent photons [2] and magnetic monopoles [3] in spin ice. Such examples raise the question of where else there is potential for low-energy experiments to inform physics relevant to high-energy...
We present a model of superconductivity in a higher dimensional generalization of the Sachdev-Ye-Kitaev model. In the normal state this model features a critical phase in (1+1) dimensions and a quantum phase transition in (2+1) dimensions. For (2+1) dimensions the superconductivity emerges around the quantum critical point. We derive the Eliashberg equations of superconductivity from the...
The nonlinear optical phenomenon of high harmonic generation (HHG) in solid state materials was employed to study different properties of these materials. In a wide range of semiconducting materials, HHG can be induced by off-resonant excitation with ultrashort strong-files pulses in the THz- and mid-IR-range. The study of HHG in TMDC materials has been shown to be particulary interesting due...
