English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Boundary conditions in quantum graph vertices are generally given in terms ofa unitary matrix $U$. Observing that if $U$ has at most two eigenvalues, thenthe scattering matrix $\mathcal{S}(k)$ of the vertex is a linear combination ofthe identity matrix and a fixed Hermitian unitary matrix, we construct vertexcouplings with this property: For all momenta $k$, the transmission probabilityfrom the $j$-th edge to $\ell$-th edge is independent of $(j,\ell)$, and allthe reflection probabilities are equal. We classify these couplings accordingto their scattering properties, which leads to the concept of generalized$\delta$ and $\delta'$ couplings.

Quantum graph vertices with permutation-symmetric scattering probabilities