Dual unitaries as maximizers of the distance to local product gates

التفاصيل البيبلوغرافية
العنوان: Dual unitaries as maximizers of the distance to local product gates
المؤلفون: Brahmachari, Shrigyan, Rajmohan, Rohan Narayan, Rather, Suhail Ahmad, Lakshminarayan, Arul
المصدر: Phys. Rev. A 109, 022610 (2024)
سنة النشر: 2022
المجموعة: Mathematics
Condensed Matter
Mathematical Physics
Quantum Physics
مصطلحات موضوعية: Quantum Physics, Condensed Matter - Statistical Mechanics, Mathematical Physics
الوصف: TThe problem of finding the resource free, closest local unitary, to any bipartite unitary gate $U$ is addressed. Previously discussed as a measure of nonlocality, the distance $K_D(U)$ to the nearest product unitary has implications for circuit complexity and related quantities. Dual unitaries, currently of great interest in models of complex quantum many-body systems, are shown to have a preferred role as these are maximally and equally away from the set of local unitaries. This is proved here for the case of qubits and we present strong numerical and analytical evidence that it is true in general. An analytical evaluation of $K_D(U)$ is presented for general two-qubit gates. For arbitrary local dimensions, that $K_D(U)$ is largest for dual unitaries, is substantiated by its analytical evaluations for an important family of dual-unitary and for certain non-dual gates. A closely allied result concerns, for any bipartite unitary, the existence of a pair of maximally entangled states that it connects. We give efficient numerical algorithms to find such states and to find $K_D(U)$ in general.
Comment: 9+2 pages, 5 Figures. Many parts from previous version are rearranged and the current version is rewritten as a regular article
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevA.109.022610
URL الوصول: http://arxiv.org/abs/2210.13307
رقم الأكسشن: edsarx.2210.13307
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevA.109.022610