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/

Global: Zendy Plus annual

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

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present an algorithmic construction scheme for matrix-product-operator(MPO) representations of arbitrary $U(1)$-invariant operators whenever there isan expression of the local structure in terms of a finite-states machine (FSM).Given a set of local operators as building blocks, the method automatizes twomajor steps when constructing a $U(1)$-invariant MPO representation: (i) thebookkeeping of auxiliary bond-index shifts arising from the application ofoperators changing the local quantum numbers and (ii) the appearance of phasefactors due to particular commutation rules. The automatization is achieved bypost-processing the operator strings generated by the FSM. Consequently, MPOrepresentations of various types of $U(1)$-invariant operators can beconstructed generically in MPS algorithms reducing the necessity of expensiveMPO arithmetics. This is demonstrated by generating arbitrary products ofoperators in terms of FSM, from which we obtain exact MPO representations forthe variance of the Hamiltonian of a $S=1$ Heisenberg chain.

Automated construction of $U(1)$-invariant matrix-product operators from graph representations