Fig. 1: Adiabatic infimum of the topological pump and the INFI loop.
From: Approaching the adiabatic infimum of topological pumps on thin-film lithium niobate waveguides
a Illustration of the adiabatic infimum of the topological edge state pump in the LNOI waveguide lattice. b, c Eigenvalues of RM lattice with N = 4 for b conventional and c INFI the pump schemes. Blue/orange colors indicate left/right edge states, while gray corresponds to bulk modes. d Aδceff in the δβ-δc parameter space. Blue and red trajectories represent the conventional and INFI pump loops, respectively. e Aδceff and the conventional (blue) and INFI (red) loops in the polar coordinate, where the conventional trajectory climbs some peaks while the INFI loop follows the route in the valleys. The green arrow indicates the decreased direction for better visualization. f Integral of Aδceff for different loops. The INFI loop (red pentagram) exhibits the minimum integral value, indicating the achievement of adiabatic infimum. β0 = 1.85k0 and c0 = 0.02k0 with k0 being the wave vector in vacuum for λ = 1550 nm.
