Circuit complexity for free fermions

Circuit complexity for free fermions

Blog Article

Abstract We study circuit complexity for free fermionic field theories and Gaussian states.Our definition of circuit complexity is based on the notion of geodesic distance on the Lie group of special orthogonal transformations equipped with a right-invariant metric.After analyzing the differences and similarities to bosonic circuit complexity, we develop Neff KI5862S30G Integrated Fridge Freezer a comprehensive mathematical framework to compute circuit complexity between arbitrary fermionic Gaussian states.We apply this framework to the free Dirac field in four dimensions where we compute the circuit complexity of the Dirac ground state with respect to several classes of spatially unentangled reference states.Moreover, we show Urn Necklace Gift Box that our methods can also be applied to compute the complexity of excited energy eigenstates of the free Dirac field.

Finally, we discuss the relation of our results to alternative approaches based on the Fubini-Study metric, the relevance to holography and possible extensions.