https://doi.org/10.1140/epjp/s13360-026-07606-8
Regular Article
Chaining Property of gate typicality of two-qubit gates
Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, 632014, Vellore, Tamil Nadu, India
a
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Received:
19
September
2025
Accepted:
23
March
2026
Published online:
2
April
2026
Abstract
In this paper, we study chaining property of some measures of two-qubit operator. The non-local characteristics whose chaining property is being studied in this paper, are entangling power which is the average entanglement for a two-qubit operator being acted upon a collection of unentangled pure states, linear entropy which is a strength measure to understand how entangled the operation is, and gate typicality which not only indicates the intrinsic non-locality of the gate but also serves as a complementary quantity to entangling power in analyzing the entanglement properties of bipartite unitary operators. The chaining property of any operator entanglement measure presents us with a lower bound on the number of two-qubit entangling gates in order to execute a given operation. In this paper, we observe how dual unitaries and perfect entanglers will always satisfy the chaining property, while the evidence is mixed for SWAP
and T-Duals. We find that linear entropy provides a somewhat clearer picture of chaining property than gate typicality. Overall, this shows that chaining property has a strong correlation with entangling power and gate typicality.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
