We find that such nonlinearity coaxes non-reciprocal excitations—so-called non-Hermitian skin waves5,6,7,8,15,16,17,18,19,20,21,22, which are typically unstable—into robust one-way (anti)solitons. We harness such non-reciprocal topological solitons by constructing an active waveguide ...
It also has reflection symmetry Mx (chosen to be σx to meet the Hermitian requirement70) that anticommutes with T and P. When qθ and qϕ are both even [e.g.,\((\theta ,\phi ){\mathrm{/}}2\pi = (1{\mathrm{/}}4,1{\mathrm{/}}6)\) in Fig. 3e], Hs has two ...
These results open novel prospects for the topologically controlled generation of light in active nanophotonic structures with topological phases and the exploration of radiatively coupled topological states in non Hermitian systems. 6 BIC lasers Open systems generally lose their energies due to the ...
As any 2 × 2 Hermitian Hamiltonian, it is a linear combination of Pauli matrices that can be physically interpreted as an effective magnetic field acting on the Stokes vector, that is, Hk = H0 + Ω ⋅ σ, where H0 is the diagonal kinetic energy part, σ is a ...
In general, a function f( Á ) of an Hermitian matrix H ¼ UDUw, diagonalized by the unitary matrix U and by the real diagonal matrix D, is defined as the function of the eigenvalues f(H) ¼ Uf(D)Uw. Positive semidefiniteness of the quantum geometric tensor. In equation (22)...