We review recent developments in the research of nonlinear and nonequilibrium
phenomena in solids focusing on their geometrical aspects. We start with introducing the …

The novel spin-triplet superconductor candidate UTe 2 was discovered only recently at the
end of 2018 and already attracted enormous attention. We review key experimental and …

We show that finite current in superconductors can induce topological phase transitions, as
a result of the deformation of the quasiparticle spectrum by a finite center-of-mass (COM) …

Non-equilibrium engineering is becoming a seminal way for realising novel quantum
phases that are unimaginable in equilibrium. In particular, Floquet theory applied to …

We present a scheme to control the spin-exchange interactions by manipulating the orbital
degrees of freedom using a periodic drive. We discuss two different protocols for orbital …

We investigate theoretically the nature of laser-irradiated Kondo insulators. Using Floquet
theory and the slave-boson approach, we study a periodic Anderson model and derive an …

We study the effects of photoirradiation with circularly polarized light on the Dirac half-metal
state induced by the ferrimagnetic order in a triangular Kondo-lattice model. Our analysis …

Discrete quantum walks are periodically driven systems with discrete time evolution. In
contrast to ordinary Floquet systems, no microscopic Hamiltonian exists, and the one-period …

A discrete time crystal is a phase unique to nonequilibrium systems, where discrete time
translation symmetry is spontaneously broken. Most conventional time crystals proposed so …

Despite intensive searches for topological superconductors, the realization of topological
superconductivity remains under debate. Previous proposals for the topological s-wave, p …