Circuit Complexity in Topological Quantum Field Theory
Abstract
Quantum circuit complexity has played a central role in recent advances in holography and manybody physics. Within quantum field theory, it has typically been studied in a Lorentzian (realtime) framework. In a departure from standard treatments, we aim to quantify the complexity of the Euclidean path integral. In this setting, there is no clear separation between space and time, and the notion of unitary evolution on a fixed Hilbert space no longer applies. As a proof of concept, we argue that the pants decomposition provides a natural notion of circuit complexity within the category of 2dimensional bordisms and use it to formulate the circuit complexity of states and operators in 2dimensional topological quantum field theory. We comment on analogies between our formalism and others in quantum mechanics, such as tensor networks and second quantization.
 Publication:

arXiv eprints
 Pub Date:
 August 2021
 arXiv:
 arXiv:2108.13427
 Bibcode:
 2021arXiv210813427C
 Keywords:

 High Energy Physics  Theory;
 Quantum Physics
 EPrint:
 47 pages, 8 figures